Dry humping is a sex activity performed while completely clothed. It is, in essence, two people rubbing their groins together through their clothing to receive sexual stimulation without intercourse. It can sometimes involve other acts, but as soon as the clothes come off, it's no longer "dry humping." It's usually seen as a safe alternative to sex, since no body fluids are exchanged, even though one or both partners may orgasm. It is also a way to receive sexual stimulation without full intercourse, in the ev...

Dry humping is a sex activity performed while completely clothed. It is, in essence, two people rubbing their groins together through their clothing to receive sexual stimulation without intercourse. It can sometimes involve other acts, but as soon as the clothes come off, it's no longer "dry humping." It's usually seen as a safe alternative to sex, since no body fluids are exchanged, even though one or both partners may orgasm. It is also a way to receive sexual stimulation without full intercourse, in the event of wishing to remain celibate (in the strictest sense, of course -- since realistically speaking, it's still possible to "have sex" without engaging in intercourse).

There is a lot of information available on the web about it. Just do a google search; but be wary, a lot of the information on this subject is not 100% reliable. Trust medical websites more than public forums.