I'm having issues with my bf around other girls idk Wat I shud do helpppp?

Kay so my bf is qute girly so alot girls talk to him etc but I think it's flirting so heres the problem two girls Love to talk and joke around with my bf he's 17 I'm 15 this girl Kira, (18 yrs old) was his neibor for as long as I cud remember but her family moved to NYC she's a tramp no gunna lie she's yur typical scene slut (hes dated 3 of those before me) and she flirts with him calls him txts him 24/7 and tells him she loves him she sends him pix and ims on gaia? Idk WTF that is but anyways I talked to him and told him I don't like her but he started calling her again onto of that there's this girl named Brie at school she's scene too and makes him bracelets and flirts with him too they talk and joke and stuff Wen I'm not around he talks about me but it's just about or something anyways she's kinda heavy but my b isn't too skinny or but that doesn't matter to me Caz I only care about the love and loyalty in this relationship but I'm skinny and very fit and one of the schools hotties ( says everybody In the school but I have emotional and confidence issues so I'm very negative about myself) anyways I've had a very abusive relationship before this and abuse parents I have alot Of issues already I feel like since I'm not scene (I'm like a hello kitty Lolita girl) I feel kinda weird and less desirable as a gf :/ idk what to do about those girls it really bothers me I got cheated on alot b4 And it hurts alot.. Today hE lied about Brie and walked home with her I hate being around her she has this look in her eyes like she truly loves my maybe she deserves him ... Idk please help? Sorry it's so long pleAse help or add me on fb To chat rain-Lydia smith