Ah, the age-old friends with benefits situation.
However, friends with benefits also come with a few asterisks. Both of you need to be on the same page in case either of you start developing feelings for each other.
Same thing goes if one person wants to end it. You both have to be okay with the end result.
The main point of having a FWB is to have amazing, satisfying sex. Having casual sex can be emotionally tough, for some more than others.