I've been running around with the unnaturally sensitive status for a while now. Not sure how to get rid of it, and I'm not even certain it wasn't a bug that I got it in the first place.
I received it when trying the different options available when "paying with your body" after getting hypnotized. It only happened on the fourth or fifth time when I decided to tease Rinny while having a dick.
Also at that point in the game I had only just freed Cassie, so if I hadn't known how to do it, it would have taken me ages to get to UNA, where I was then told after an examination I should simply stop cumming. But I don't know if it means for a certain amount of time or steps, because just going to bed repeatedly and lowering my arousal with angel milk did not work. I've tried that 15 times in a row.
Edit: I just remembered I also got early stage pregnancy at exactly the same time.