Yes, virtually every sexual interaction is optional (no matter the gender origin, female or male) for the main storyline and most interactions (from jobs to having friends). For the most lewdest jobs (cleaning lady in motel, barmaid in revel street) you'll most likely get groped or worse, unless you can avoid it with stats.
Some sidequest apparently might require doing sex, though i'm not 100% sure. Also, you can easily avoid being forced into anything by training into physical soon and keep a high mood and wearing enough clothing (basically normal)