What would u do?

I know most people put up relationship problems here, but im in no relationship problem. Im actually torn between two people. I like both of them for different reasons. One i have known now for a year and she just recently broke up with her boyfriend. I have been told by many people that she would not be upset to hook up with me and im fine with that. On the other hand, i just met this girl and we flirt constantly. Her roommates have told me that shw would not mind hooking up with me. Neither of them know each other and the possiblity of getting caught is slim. The only thing i see as a problem is that i might, in the future, want to start a relationship with one of them so i dont necessarly want to do anything to get myself into trouble. For instance, i dont want the "Oh you were faithful while we were hooking up right. U know, we were exclusive." I dont want to sit there and be like no and lie, cause the main thing with me in a relationship is trust. So should i just wing it and go for the double play, or should i just pick one and hope for the best.
Oh and by the way, im going away with one of them on spring break to Canada where no parental supervison would be and the other has just invited me to her house for a weekend. Please help me and try to keep it on topic. Also, please try and give advise and not spam the hell out of this thread