Lets talk about fuck buddies

AKA "Friends with benefits"

has anybody successfully kept it going?

Seems like, for me, they start out great but quickly turn into the girl developing feelings for me. Don't get me wrong I DONT want to just have sex without any strings but I just have not much time in my life for a full on relationship. SO, i think the fuck buddy thing is great - but it never lasts long for me.

Girls, your opinions for/or against.
Guys what are your experiences and/or advice.

ready, set GO!