the guy I'm talking to and my old best friend (tea)

ok so my old best friend went to a guy I liked and got his Instagram for me (we are still friends we just grew apart) he dm'd me and we talked and I really REALLY liked him. fast forward 2 MONTHS and he just gets dry, I ask whts going on and he says "nothing." 

so I assume he doesn't like me anymore, I still have feeling even 2 months after this and he messages me and asks if it would be weird if he likes me still and I said no cuz I like you 2

he then goes on to talk and we have been talking and making plans for the last 2 weeks because of a camp we were both going to.

I can't go to camp.

my old best friend is there and they talk and he calls her a 10/10 2 says after saying he wants to date me.

and he wont stop staring at her. so yeah I hate him for it but I still really like him. 

any ideas on what I should do?