He has a girlfriend...

I met this guy about a month ago and we had been talking. At first just as friends but now we have kind of fell for eachother. He's been open in the past(pre-falling) that he's very unhappy with his girlfriend and has been for a while he just is scared on how she will handle it. I said I'm willing to wait but I think I'm done waiting. I don't know what to say to him so that I don't sound like I'm pressuring him but I also want to make it clear that I'm not gonna wait around forever. If anyone has advice let me know below! I appreciate it! I also want to clear up that we aren't doing anything or talking innapropiately I'm not a cheater never will be.