Demon Wedding Rituals and Traditions

Demon society recognizes three formal styles of courtship that can lead to marriage - and the option of an unlabelled union, as demons consider the act of marriage to be a civil matter. As such, most demons wed partners they have been with for several centuries or more - or chose not to wed at all, if they and their partner(s) are of equal means. 
While each style of marriage has varying regional traditions, there are many core aspects that are the same across the realm.

History

“The Demon Realm has three main kinds of marriages,” Feyl supplied, “And each is the purview of a different deity. Maenscul is the Deity of Kings, but their domain also includes sexual relationships, so they oversee formal marriages of that kind.”
“S-” Meir’ril paused, “Sexual marriages?”
Braelin chuckled softly, “I was also surprised by that.”
“Well, it’s the third component of what makes every demon,” Feyl snorted, and started counting them off, “Maenscul crafted our bodies out of clay, Vislaelos’s mother Carmesso gave us hearts so those clay forms would never dry out, and Nosu gave us souls by making our heads as kilns to carry a flame.”
“So there are three main relationships,” Minaz took over, “Earth relationships based on the compatibility of the body, water relationships based on the compatibility of the heart, and fire relationships based on the compatibility of the soul. Sexual, romantic, and queerplatonic.”

-Demon King's Gardener, "In Which a Midday Meal is Shared"

The three culturally recognized forms of courtship are based on the relationships of the deities that rule over them. 
Maenscul, Deity of Kings, rules over sexual relationships - also known as earth relationships, as they are based on the compatibility of the bodies Maenscul crafted for demonkind. Maenscul is not known to form romantic nor queerplatonic relationships, but many of their strong friendships include sexual relationships. Being the kind of relationship favored by their main deity, demon society of course considers these relationships to hold equal weight with the other two kinds of courtship.
Nosu, Deity of Wisdom, rules over queerplatonic relationships - also known as fire relationships, as they are based on the compatibility of the souls Nosu lit for demonkind. Nosu and fos spouse, Vouscu, have a queerplatonic relationship - and it is from their relationship demons derived the concept. While not all queerplatonic relationships resemble the one between the deities, Nosu and Vouscu having no desire for sexual relationships which others that do not feel romantic feelings may have, the core idea of a dedicated life partner based in strong platonic feelings comes from the celestial pair. 
Vislaelos, God of Romantic Love, rules over romantic relationships - also known as water relationships, as they are based on the compatibility of the hearts creafted for demonkind by Vislaelos's mother, Carmesso, Goddess of Storms. Prior to Visleaelos discovering his domain, Carmesso ruled romantic relationships - though her most famous relationship with Cegae was often fraught with turmoil due to their equally volitile tempers. While she certainly represented the passion often found in romantic relationships, her son presents a more rounded representation with his stable and gentle marriage with Soken, God of Blacksmithing. 
There are also those who chose not to define their relationships by any of these definitions - often because they feel they do not match any, or that their relationship matches more than one of the culturally recognized three. These relationships have come to be ruled by Vemera, Goddess of Judgement - primarily as those wishing to be wed without defining their relationship only participate in the civil portion of the typical wedding process, though many have personal ceremonies as they desire. 
Demons are culturally polyamorous, and many participate in multiple relationships. For some, they may only participate in one form of relationship with multiple partners - others may participate in multiple forms of relationships in addition to having multiple partners. As such, weddings may include two or more pariticipants. However, it is not required that all members of one relationship participate in another - that is to say, an already married couple may chose to marry a third together, or individually.

Execution

All weddings follow a similar process - those wishing to be wed go to the nearest Temple of Vemera to state their intent. There, they will make their appeal to a statue of the deity that presides over their kind of relationship to be wed. If the deity does not object, the date for the Joining Ceremony will be set and recorded for the Temple's records. 
Those participating in a sexual marriage often have their Joining Ceremony in the Temple to Maenscul found in all major cities, presided over by a priestis to the Deity of Kings. Depending on the dispositions of those being wed, the ceremony may include sex acts - and as such, do not typically include family members. As many demons do not maintain strong familial ties, this is usually not seen as a great hardship. 
Those participating in a queerplatonic marriage often have their Joining Ceremony at home or in the Temple to Vouscu. Nosu typically has a small temple within their comascas's larger temple in all major cities, rather than fos own freestanding temples. As Vouscu is Deity of the Hearth and Home, it is equally common to have the ceremony at home - usually a matter of means and preference of those being wed. As Vouscu also rules over platonic relationships - specifically friendship, sibling bonds, and non-blood familial bonds - it is common to invite as many friends and family as possible. 
Those participating in a romantic marriage often have their Joining Ceremony at the Temple of Vemera, with a member of Vislaelos's clergy presiding - though more commonly, they will do so at a smithy, with a blacksmith presiding. Soken does not have a temple in most cities, and Vislaelos has only two freestanding temples, with small temples within his husband's much like Vouscu and Nosu. As such, blacksmiths - as the followers of the love god's husband - have long had the authority to preside over romantic ceremonies, and smithies are more accessible than either god's temple for most demons. For those determined to have a preistis preside, however, one usually resides at Vemera's temple. 
Those participating in an unlabelled marriage most often have their Joining Ceremony at the Temple of Vemera, presided over by one of her priestis. Though, for those not concerned with having a wedding under the purview of a deity, they may have a private Joining Ceremony at a location of their choosing with a friend or family member to preside, if anyone. 
Joining Ceremonies are considered optional in demon culture - an announcement and celebration for others after the acceptance of their relationship by the deities. As such, while these common locations for Joining Ceremonies exist, they are not mandatory - so long as those being wed can find their preferred presiding preistis or other master of ceremonies, they may have a Joining Ceremony wherever they wish.

Components and tools

“Why would you give someone a weapon as a courtship gift?” Braelin asked, and Jurao could picture his frown of confusion.
“To show you wouldn’t use it against the person you’re interested in,” Feyl replied breezily, “And that you don’t mind if they use it against you.”
“Shouldn’t you trust them not to use it that way?” Braelin replied.
“A very human perspective,” Feyl sighed, coming into view in the doorway. As usual, he walked inside without a care, “We hope someone won’t use a weapon against us, but if given as a romantic gift, we’re communicating that we feel strongly enough that being betrayed would not diminish those feelings.”
Braelin hummed, walking next to Feyl as he said, “I suppose since it’s a declaration, you can’t demand reciprocation.”

-Demon King's Gardener, "In Which Jurao Loses His Nerve"

Each style of courtship has different gifts, rituals, and traditions associated with it - which include wedding gifts and accoutrements. 

Sexual Courtship

Something sexual and romantic courtship have in common is that displays of physical prowess - usually in pure strength or fighting skill - are both considered means of flirting. Gifts associated with sexual courtship typically include wunas wool items of clothing or jewelry made from wunas horn, as the animal is strongly associated with Maenscul. Other gifts may include bells of desire - as the flowers are used to create aphrodisiacs, or other flowers. 
For a sexual Joining Ceremony, the traditional color theme is white - as gold, Maenscul's main color, is considered the color of Kings and other royalty, their secondary color of white has become the color of choice for Joinings they preside over. Typical wedding clothing for sexual weddings is both plain and sparing - many with the wealth to afford it chosing gauzy or otherwise partially transparent-fabrics. Yellow sunstone is often fashioned into a bronze, mantle-style necklace as a symbol of the marrying parties' bond. 

Queerplatonic Courtship

Queerplatonic flirting often invloves engaging - or attempting to engage - another in a debate, often of a subject known to be a passion of desired party. Poetry is another form of queerplatonic flirting, though less common. Gift associated with queerplatonic courtship include books or scrolls, in relation to Nosu being the Deity of Wisdom, or items made with kiln nester feathers or leather, for the bird's association with fos comascas Vouscu. 
For a queerplatonic Joining Ceremony, the traditional color theme is green - as Nosu is also Deity of the Green Moon. Loose-fitting, flowing clothing similar to that worn by Nosu is typical wedding fare - as well as multicolored veils that imitate Nosu's "hair" of polar lights. Red jasper - tied to Vouscu being Deity of the Red Moon and as a member of the flint family - is often fashioned into a hanging necklace of silver as a bond symbol. 

Romantic Courtship

Romantic flirting, as stated, includes acts of physical prowess, specifically feats of strength - but it can also include calling out the desired party's poor behavior. Demons often develop feelings for those who able to humble them, finding earned verbal take downs equal to physical strength in terms of attractiveness. Gifts associated with romantic attraction include weapons and armor, both in relation to Soken and to the volitility of Carmesso and Cegae's relationship. 
For a romantic Joining Ceremony, the traditional color theme is black - for the black blood flowing through demon veins. Often, those being wed wear only pants or skirts - as is the preference of Vislaelos, as it allows him to better show off his figure. Some may chose to incorporate pieces of armor, to honor Soken as well. Obsidian is usually fashioned into a torque-style necklace as a bond symbol - with the wealthy and daring using Mahen's Tears specifically. 

Unlabelled Courtship

As is the nature of courtsips that do not fit traditions, unlabelled/undefined courtships can take many forms and include a wide variety of gifts and displays of affection as they fit the pariticipants.

Primary Related Location

Demon Realm