Have been having conversation and email and text mess with a man from another state that I met on line.?

Im aware this might be a long shot. Seems for real and we have both told each other we love the other. Will be meeting each other first time in June. We know what we look like, have talked about everything under the sun. Sometimes though I hear from him a lot then sometimes lately he doesnt call when he says he will right away, or is affectionate one time and I feel a little less other times. This could of course be because he is a man or because he is a former marine and set in his ways? I might just be taking it the wrong way. We are going to Las Vegas in Novemeber, he is paying for everything. Im not sure if he is always for real? I dont want to seem to overbearing or suspicious or jealous at that. Not sure what to do?