Hands up
I would say that when I was most heavily into smoking rocks I was also most heavily into whippin' it (whip it good). When I started smoking I didn't even think about sex because the drug high was still novel. A couple of years after I started I would move towards getting a goodly amount, locking myself into the basement, and trying to get a good lungful while I stroked.
This was unsatisfactory for a couple of reasons. One - no girl. Two - I'd always think that I should have just one more hoot before rubbing one out. This meant a whole lot of perfectly good wanks would turn into repetitive tweaking. I can remember one time that I spent most of the session trying to get the red/green balance just right on the TV. Lots of rewinding the tape (usually not porn, more Playboy/Penthouse kind of stuff) to try and synch the hoot with the on-screen hottie with the timing of the money shot. Usually the money shot would have to wait until about an hour after I had run out of rocks.
I probably missed out on a whole lot of real sex because I was wasting so much time trying to fool myself. Still, one of these days I want to get a lungful and get off before I blow it out (I mean exhale). I have a feeling that this will require getting 'almost there' before I take my first hit. Usually I can't wait to take that first hit though.
I think anything that releases dopamine (any pleasurable experience?) can be 'extended' through coke use. This is why I like to use cigarette ash for my hits. (Tobacco releases dopamine.) Then the coke keeps the sensation going. So, whatever you were doing to release that dopamine gets associated with the pleasure, except that now you're linking coke with the pleasure. Unfortunately, sometimes you get so used to enjoying the 'extended' pleasure that normal experience doesn't do it for you anymore. And then it sucks to be you unless you're willing to wait for your brain to re-normalise. Which might not happen any time soon. I mean, how are you going to keep them on the farm once they've seen Paris? (As it was said of soldiers from middle America returning from WW2.) It changes you, yes.