im stuck in a love triangle, help?

ive liked this guy for 3 years and my feelings for him are really strong. recently i found out that he's liked me back the whole time, but now he also likes my ex-best friend and asked her to formal last week (she said yes). so he likes both of us now but he likes my old friend (R) more because shes less moody than me, and me and my ex-bff have been on civil terms for awhile, but i dont know what to do from here. me and the boy (L) talk constantly and he always flirts with me but he also talks to R a lot too. but i feel like me and L have more chemistry than him and R because we are both perverted but can be moody and sweet and joke around with each other, while R is just plain happy and giggly in an annoying way. what if R likes L back (i dont know if she does)? it makes me a little mad because i used to always talk about how much i liked L to R, and now shes backstabbing me and going to formal with him. help? i dont know what to do, because i dont know if anyone else knows that L likes 2 people (besides my friends) and i dont want to make him mad by telling R or any of L's friends and discussing it with them. and how do i approach R about this, and how do i talk it through with her?