signs he’s keeping ties with his ex?

Hes friends on FB with his ex and her mom. They dated a little over a year in college. I looked at his ex’s IG and saw that she lives in Austin and he keeps telling me how he hopes to move to Austin after graduation. I know that a lot of people want to move there, but I just had a gut feeling it was for her. Other than then he treats me very sweetly so should I be concerned? We’ve only went out once. But he’s very persistent and seems to show a lot of interest in me...  so I just need some advice? What would you do? *my first relationship so I’m new to this stuff*