He says that if he didn't want me, he would simply leave. But how can I tell him that what he is doing is not enough?

We dated after high school, then lost touch for 20 years. Last year, we found each other again, and within a month, we were engaged. Now we live together in my house. I have decided to get teaching certification (on top of B.A.) so I can steadily provide for us. While I’m in school, he works full time and then some to pay the bills. He’s really good at what he does (builds stages and sets) but he wouldn’t have that job if I hadn’t introduced him to the right people. He’s paying MY bills, not his own.
My problem is, he is more intimate with his online gaming community than he is with me. My friend comes over in a dress and gets a huge reaction from him. He picks fights with me about dinner. He only tries to be cute or funny when he thinks I’m upset with him. Then he tries for about a minute. He’s a man of his word, so I know that when he says he would be gone if he wasn’t interested he means it, but WTH? Why is this so impossible? I’m supposed to be happy in a relationship (vs. being alone for 13 years), but this is so hard to enjoy with his behavior, or lack thereof. Suggestions? Comments?