He might have a girlfriend...

So this guy has been messaging me and he's super attractive we have talked on and off a few times and it's ok. He is in the Navy and in Japan, he gets out in April and will be moving back this way. Now he's asked me out and is making plans for a date, but he has a gf now. She's in Japan, she's Japanese he said they won't work when he's back because he's not bringing her back. So idk what to do I mean it seems like a really unsure situation I obviously want marriage and babies immediately and I doubt he will just coming back. But he's so attractive ! Not sure what to do