Some entries that I thought would be good for the New Uses for Existing Spells part of Sexual Magic:
Binding: the chaining version of this spell can be used for bondage for purposes of sex.
Calm Animals: This spell merely pacifies animals, but does not necessarily incline them to view the caster as more favorable as a sexual partner. Attempting to mate with them where they do not desire it (that is, attempted rape) counts as a form of attack, and they may defend themselves as such while under this spell’s influence. Any form of mental arousal in the animal (Horny, Lustful, or Delirious) is negated by this spell.
Calm Emotions: While this spell does stop the object of sexual advances from becoming vehement in refusal, it doesn’t make them thusly more inclined to accept advances where they normally wouldn’t. Attempting to rape the target of this spell is an attack, and they may defend themselves normally while under this spell’s influence. Any form of mental arousal (Horny, Lustful, or Delirious) is negated by this spell.
Entangle: This spell is also useful for those who enjoy being bound…or for someone looking to subdue victims to sate themselves on.
Gaseous Form: One particularly odd fetish involves having a sexual partner actually inhale someone who has this spell cast on them! They always exhale the person before the spell ends (for fear of their life), but describe having someone else inside them as being a “wonderfully intimate and powerfully erotic” experience.
Gate: This spell can be used to open a gate to a succubus or erinyes to enjoy in bed. However, they are under no compulsion to come through the gate nor obey the spellcaster, making this spell not as useful as other planar summoning and controlling spells.
Gentle Repose: This spell is choice among necrophiliacs, since it keeps the corpse from decaying.
Hold Animal/Monster/Person: These spells paralyze victims, making them prime choices among sexual predators, since it keeps their victims still and unable to cry out. Most rapists love the sensation of power this gives them over their victims. Other times its used among couples as a show of intimacy, since one partner would have to trust the other very much to let themselves be paralyzed, since their partner could do anything with them…or to them.
Instant Summons: The perfect spell for summoning a much-loved sex toy into your hand.
Magic Jar: Jealous spellcasters have been known to use this spell to take over the body of someone that they themselves were spurned in favor of. In some cases, the spellcaster is content to just have sex with the desired person in the victim’s body, but other times they deliberately do things that will ruin the victim’s reputation so that the caster will then be seen as the more favorable choice.
Mordenkainen’s Magnificent Mansion: Need a place to have a hidden tryst? This spell is perfect for a quick place to enjoy affection in private.
Major Creation: Virtually any type of sex toy can be created with this spell.
Minor Creation: Relatively small, simple sex toys, such as dildos, clamps, etc., can be created with this spell.
Reduce: The caster can use this spell to make herself smaller, but cannot be used to increase the size of a specific body part. It could be used to make the caster go from one size category to another (depending on level and starting size), which may have effects on the size of their vagina.
Telepathic Bond: Partners who are open with each other find this spell handy in the bedroom, as it allows them to communicate even when their mouths may be busy with other things. It’s also said to be very intimate to be able to speak telepathically to your partner while making love.
Unseen Servant: An unseen servant can be commanded to perform a carnal act, which it does with mindless repetition. However, for some lonely casters, the sensation of the repeated, single-minded stroking or rubbing is pleasurable enough, while others have it do something to themselves or a partner while engaged in sex, since the servant is invisible and shapeless.