Girls, why do you agree to friends with benefits (fwb) relationships?

OrionRose
I've seen this trend my whole adult life and since being on GAG, I'm constantly dropping opinions about it:

1) A girl says yes to friends with benefits relationship with a guy. No strings attached, no agreements.

2) Girl and guy share lots of intimate hours together. Still, no commitment, no agreements.

3) Guy finds a girlfriend with whom he makes a commitment and makes agreements.

4) friends with benefits girl gets upset with guy because he a) got a girlfriend, b) stops returning her text and calls, or c) all of the above

5) friends with benefits girl is shocked and upset because she thought there were "feelings" between them and that they were "friends." Guy is branded an asshole for breaking her heart.

Help me to understand what is happening here. Why do girls/women who are naturally more relationship oriented and tend to get more attached quicker in sexual relationships choose to say yes to the friends with benefits dynamic? What are you getting out of it? How is it ever fulfilling? And why the hard feelings when he gets a girlfriend?
Girls, why do you agree to friends with benefits (fwb) relationships?
18 Opinion