if i dont know the person very well, i always use one. i dont want any std's or little trowsersnake's running around . i only used one once with a chick i didnt know that well, but it was almost like i was raped . i was absolutely trashed and i remember flirting with this chick most of the night, then just a few brief, blurry images of her sucking/riding my dong and when i rolled over the next morning she was next to me. hot as hell, but a slut.