Park threesome (mff)

Forgive me this is my first time writing something like this but here goes. Sorry it's a tad long.

Bit of background first, I'm 26, 6'3", slimmer but trying to bulk up, 165 lb and a bit over average dick. My girlfriend ashley is 27, 6', has a gorgous hourglass shape, toned legs and great ass from running and exercising regularly, and fantasic 38DD breasts. Sarah, her bff is a bit cubbies but has everything in the right places, massive 40DDD tits, and a cute round face. We have fooled around with her once before when we were really drunk and despite Ashley being a bit nervous at first she got right into it. But this story isn't about that, this is about our most recent time with the three of us.