How long do ppl talk?

I’ve been seeing this guy for a little over a month now. We went out with mutual friends one night and hooked up. I thought that was it but a few weeks later we started to hang out all the time. He’s introduced me to almost all his friends and has told me he’s really happy that they like me. We’re actually going on a trip this week with his friends and I’m excited. But last week he texted me making we were on the same page about everything. I mentioned that if I’m seeing someone/talking/etc that I don’t really entertain anyone else and that I wanted to make sure we’re on the same page as that. All he said was “it’s all good”. I’ve asked about this twice but he just says that, so I’m assuming he agrees we are on the same page ? But what I really want to know is how long do people see each other for? I’ve known friends who have seen each other for months and others who have only seen each other for a few weeks ???