Yikes! I am not relationship expert but...seems there is a disconnect between sex for fun and relationship. My only observation is that sex for fun involves a bit of seduction, not always but mostly. This means if someone wants to try something a bit off the beaten track, it might reasonably begin with seduction. Seduction would maybe bring the other party along at that party's own speed. Being in a relationship might blind us to the need for seduction in sex simply because it has become routine. But if you ask me, slow seduction and talk about needs might be better for those of us observing from a distance, than wildcatting.