Should i date her still? PLZ HELP ME!!!?

So, yesterday i was talking to my best friends girlfriend, and they both chicks, so there bi. Anyways i was talking to her on facebook and she said '-makes out-' like if she was here she'd be making out with me. So we're dating now, and my bestie says shes not mad, but i REALLY think she don't want us to date. Also Kristy ,(the girl i was talking to on fb), broke up with her boyfriend Dale. So now, i'm dating Kritsy, Kristys dating me and my bestie. So my besties mad and dont feel confy with us dating, so do you think we should break up? Also im dating a 18 year old guy. Kristys 14 and im 13 and my besties 14. ALSO PLZ NO HATE COMMENTS ABOUT I SHOULD'NT BE WITH A 18 YEAR OLD!!!!! WHO CARES!!!!! NOT MEEEE!!!!! thanks, best answer gets full rating! (: