Group Hug

16M
Im a sexually active teen. Ive been in a very good relationship for about a year now with a nice girl 15, but something keeps bothering me. My girlfriends sister 1 year older is always subtly flirting with me when im at their house. and the problem is i like it. whenever my girlfriend is not around i always peck her cheek or something. so finally, 2 days ago, my gf went to the store, while i was at their house, and her sister walks in. we end up making out on a bed and undressing a little. all of a sudden my gf walks in the room. but she doesnt look pissed. she comes over to the bed and begins kissing her sister. then they start taking off my clothes and we start having a 3some.
I must have orgasmed 3 times.