My best friend and my boyfriend had a thing going on..*

Me and mybest friend have been best freinds for 6 years and 2 years ago this guy came into my life so we have been dating off and on for those 2 years and one day me and him were in this fight so him and my best friend deciding to go shooping together and then after that they went back to her house and she was pushing on his dick and juss being very slutty and then he showed her his dick and even though they didnt actually do anything its the fact that she has seen it and that she would do that to me. i dont know what to do about that at all she tells me its no big deal but to me it is. I told him that i know and he said nothing and then 2 mins later said yeah shes a slut i found out from her sister and i also found out this... me and my boyfriend were on a break and i met a different guy i really liked him not love but liked and then we went on 2 dates and then he started calling my best friend because my boyfriend found out and told him if he touches me he will kick his ass so the guy i went on 2 dates with starting ignoring me and started calling my bestfriend well the other day he asked her out and she said i dont know and she hasnt said one word to me about it i found out from her sister also. dang im in a mess! im open for all the advice u have thanks jennyk*