Well, I do experience "hypersexuality" with meth (and armodafinil), even at therapeutic doses time-to-time. But usually, I don't try to engage in sexual activity when I'm on stimulants because even though my brain is psychologically "super horney", I find it very, very hard to get an erection. It has happened to me on multiple occasions where I get super horney on stimulants and try to engage in sexual activity with a woman, and I just couldn't get hard on every one of these occasions when I'm on stimulants. I experience erectile dysfunction more with meth than armodafinil (probably due to a temporary lack of blood flow to the penis caused by stimulant drugs).
But if "he" (or if you're asking for yourself) gets horney, I'd suggest just rubbing one off to the most "stimulating" kind of porn you prefer in the movement; that'd decrease his likelihood of actually going out and engaging in whatever fantasy one's monkey brain suggests.
That works for me; "post-coital tristesse" or what layman calls "post-nut clarity" is a real thing.