My Boyfriend Talking About Me To His female Best friend

Me and my boyfriend have been fighting so much lately. It's just over more stupid shit after stupid shit. Now I find out he's talking about me to his female friend. When I brought it up he told me I shouldn't be looking through his phone and didn't say anything wrong he was just venting. I get he's been friends with this girl for a long time. They go way back. They used to live together as kids, but I told him you telling her this will make her think she can come between us in our relationship. He gets pissed and said " If we wanted to fuck that would have happened a long time ago. We used to sleep in the same damn bedroom. As teenagers!" What do you guys think of these texts.

Update: So I saw he got a message from Leah while he was taking a shower and it looks like he's planning on spending the night there!