How risky is male-to-male kissing on the mouth? It could be either closed-mouth with lips only or open-mouth with tongues. How safe are both types of kissing? Could dangerous germs like cold germs or even AIDS germs be transmitted that way (especially when kissing with tongues)? Also, what if one of the men is a heavy smoker and the other is a non-smoker? Does that fact increase the risk of possible disease transfer through kissing? This is a serious inquiry. It would be nice if someone with a medical background could respond--as well as anyone else, of course. Thanks!