Sexual arousal is a key element of human existence and the most natural thing, because it's vital for wanting to fulfil the only real purpose in human life: procreate.
I mean, let's be honest: if it wouldn't feel good and be such fun, nobody would do it. Spending time and energy rubbing bodies against each other is profoundly dumb. So, perhaps this is a signal from your body: go and mate, make babies, fulfil your duty, before you leave this place.
In any case: I'm sure you'll find a way to "rub it all out" to be able to focus on whatever else you want to do that is non-sexual.
