Where the word comes from
Vanilla is the plain flavour, the one you get if you do not ask for anything else, and the kink scene borrowed it in the same spirit. Early uses come from the gay leather community of the mid twentieth century, describing people outside the scene. It spread with the rest of the vocabulary and now gets used far outside kink, for anything plain or default.
Is vanilla an insult?
It can be said as one, and sometimes is. In the community itself it is mostly neutral: a description of what someone is not into, the way a vegetarian is not into meat. Kink is a preference, not an achievement, and a person who enjoys vanilla sex is not missing something any more than a person who prefers tea is missing coffee. If someone uses the word to sneer, that tells you about them.
Vanilla and kinky together
Mixed couples are common, and most of them work. What helps: the kinky partner says what they want in plain words rather than hints; the vanilla partner says what they are curious about and what is a no; both treat a no as an answer rather than an opening bid. Many vanilla people discover a kink or two this way. Many do not, and the relationship stays good because the kink is met elsewhere, or not at all, by agreement.
Being vanilla in a kinky space
You are allowed. Munches welcome curious people and partners, and nobody at a decent event will push you to play. Saying “I am vanilla, here with my partner” or “just exploring” is a complete sentence, and most kinksters will take it as the honest answer it is.
Questions people ask
What is the opposite of vanilla?
Kinky. Kink covers everything vanilla leaves out: power exchange, restraint, impact, role play, fetish. Both words describe preferences, and many people are some of each depending on the partner and the day.
Can a vanilla person date a kinky person?
Yes, and it happens all the time. It works when the kinky partner is honest about what they need, the vanilla partner is honest about what they will and will not try, and both agree where the rest of the kink goes: into a hobby, into fantasy, or, with consent, elsewhere.
Is vanilla sex boring?
No more than any other kind. Vanilla describes the absence of kink elements, not the absence of skill, attention or heat. Plenty of kinky people would tell you the best sex of their lives was vanilla, and plenty of vanilla people find kink dull.