I've read from this site that it is great having sex on meth. But i wonder the same, i would think your heart is already beating too fast and such to engage in sexual activity. Just start with a small dose, and see if you are not too antsy and jittery.
Ha ha you plugged. Seriously though, I don't think the method of taking something makes any difference regarding what you are asking about unless of course it is anal sex then I imagine your partner would get some left over done on their dick.