Helpp please guyss D:?

So basically i have ha a best friend for about a year now, shes a bit slutty, and superficial, but i reaally realllyy love her [as a friend]. ANyway she is always trying to persuade guys to be her boyfriend, aand they rarely want to , and she just ends up having loads of friends with benefits, and sending them dirty pictures every night. So we both met this guy, lets call him Carl.. and she started to really like him- like alot. So she called dibs, but we always call dibs as a joke, and so she, me and Carl met up in town yesterday, we went back to my house and he started flirting with me, i started to like him and he told me he liked me. So she went home early and me and carl went back to town, we were sitting under a bridge and we kissed.. alot, and now shes not talking to me and is reaally really pissed off because she said i was flirting with him. she doesnt know we kissed. he asked me out but i cant say yes because of her, i know she should mean more to me, but i really like him and hes amazing. What should i do ?