A relationship where a man and a woman enjoy having sex with one another, but do not see each other as potential relationship material. Friends with benfits usually never works successfully with ex-boyfriends/girlfriends or anyone else you might have feelings for. The benfits are not exclusive, buyer beware!
Dick enjoyed having sex with Jane, he was young, attractive, and successful. He didn't need any bullshit hassle of a relationship. Jane also liked having sex with Dick, she was also young, attractive, and successful and though she could do the 'friends with benefits' thing unfortunately she developed feelings for Dick, but realized it was futile because Dick was also having sex with X number of other women.
Jane dropped him like a hot potato, and hasn't looked back.