Well, there is the possibility of A&P phenomena, especially with the sexual overtones. In my experience, after you practice vipassana (or jhana) for long enough and go up the nanas (or jhanas) enough times, the mind is able to fabricate experience easier and easier.
If you're speaking in terms of practice... then
What surprised me was that I'm used to think about joy as plaesent sensations associated with smiling, or a general sense of wellbeind diffused in my body
this could be 1st jhana or mind and body phenomena.
Energy manipulation seems to be most obvious at the A&P for me, and if that's your baseline, it could be quite accessible at any time. In this territory, I find that I can make a very pleasant energetic feeling arise wherever I want in my body, with precision and speed. In terms of more bare vipassana practice, these feelings appear as bare vibrations of a pleasant nature, going very quickly. And as far as crossing the A&P goes, if I really work my mind to follow these extremely quick vibrations, they spread and my whole body gets enraptured, and the feeling of joy can explode if I so choose. I've also noticed that the intensity varies quite a bit, and if the A&P has been crossed a few times recently, the A&P can be extremely quick, not particularly joyous, and not particularly pleasant (but usually not unpleasant). What practice are you doing? If you're trying to do vipassana, that is a perfect point to go balls to the walls with fast noting (or just noticing) of vibrations. There's a ramp for concentration, and continuous hard effort and application of your technique is prime for launching across the A&P.
A&P territory is prime for working on jhana since concentration is temporarily insane, if you want to tune into the joy aspect and work on 2nd jhana. Whenever jhana is particularly available, I like to take that route and get to 4th and then do vipassana from there.