Keep running into my ex hookup lol

In this past week I keep running into this guy I hooked up with! We hooked up like a little over a month ago and then he kinda just stopped texting me. Should I text him something like “It’s so weird we keep running into each other?” When we see each other we make eye contact but don’t go up to each other because both times we’ve been in groups of people. or would it just be stupid to text him? i’m going to school soon so i don’t mind if we hooked up again