Advice needed by all polyamorous people

Okay first I want to mention I'm monogamous. A few months ago I met this guy on Tinder and we clicked we went on a date which ended up badly or really badly but then he apologized on some technicality is that where his fault so then we started talking up again and a few weeks ago he got a cat with this girl but I figured that they were dating and he calls me later that night that Tommy guy he's dating her and that he figured out that he's polyamorous which I had a look up and get myself one but I really like this guy but I don't know if I could do Polly should I give it a try? Cuz I really like this guy I haven't had a connection with a guy like this before