Most Helpful Guy
Yes, it's fine, but make sure you communicate well with each other so someone doesn't think it's more than it is. Usually friends with benefits means one or both people are open to seeing others; something more is usually monogamous. Friends with benefits usually implies some sort of attraction, so it's natural for it to grow into something more. But if you're going to make that leap in expectations, make sure to have a conversation about it.
Most Helpful Girl
I had a one night stand that turned into friends with benefits that turned into dating and now he talks about wanting to get married.
We just had a really good connection right from the beginning. And we both liked each other after getting to know one another. I think it was about 6 weeks from the night we met til we became official. But even then we still took things really slow. (Not meeting family or friends or getting super serious)