What does going out mean?

I slept with this guy the second time I hung out with him and then he asked if I wanted to go out with him, after we had sex. I said yes.So what does going out actually mean? Are we serious yet or not? We had been talking for about a month online before we met for the first time. I want to know if he will be faithful to me or not because he goes online a lot (thats where he met me) and has a buddy list with "bitches" sn's on it, I dont see him too often and he doesn't talk a lot about his job, which he works with a lot of female waitresses and he says he only talks to the female waitresses because the others are gay guys. The first time we met all we did was watch a guy movie with naked sluts in it and he stared at it, he has a lot of porno mags, even some subscriptions to some mags. He even downloaded this naked girl game on the internet and watches it. Is he immature or what? Im just wondering if he is really ready to settle down or not. He also said he was going to surprise me at work sometime by showing up (we live 45 minutes apart) and he hasn't made an effort to yet. But on the plus side, he treats me really well and is really sweet and affectionate. But these little things are bothering me, Im not jealous I just want to know why he has to have so many females in his life if he wants to settle down with me. Also could he be thinking that I will never find out if hes hooking up with someone else because we hardly see each other and we only hang out at his house and we live far apart? I dont want to ask him these things because I dont want to piss him off or make him think I am accusing him of anything. Anyone, please help me! thank you