Sounds like there's some autonomy and novelty/predictability relational dialects going on. What's wrong with him hanging out with older girls? Anyway, I would suggest talking to him about it.
Even when I explain these things to him. He just doesn't get it. Lol. I'm his first girlfriend. He doesn't really know what he's doing. But my god he's impossible sometimes.
Sigh. And just to top it all off, he called saying she was too busy, and that he wanted to come over now. I said sure, then two minutes later he rings again, and says, oh don't worry she's ready to see me now. JKfbjkerclabuirbuiehrvrfhnerf