Ladies.. please help a fella out there.. mucho appreciated!?

ok, in all honesty, if we, the male race, are talking to a female, whens the best time to kiss said female? if you know there is some "chemistry" if you will, if you feel something gurgling in your loins that has nothing to do with your (ok maybe it has a little to do with said genitalia), should we kiss you then? like at a party i mean, not like in the middle of a cl. would a (face)cheek or a lip kiss be best?