Which girl should I pick?

I am currently in a relationship with a girl I really like. However, there's this other girl who I'm sort of developing feelings for. Both girls have strong feelings for me. The girl I'm currently dating doesn't like this other girl very much. She's also extremely bossy and flips out over little things. Plus idk if I can trust her. But this other girl I can trust with my life. She's one of my best friends. She's very sweet and caring. But I'm not sure who to choose. If I pick the other girl, I will definitely lose my friendship with my current gf. Please help!!!