Dating more than one person?

Overview:
So I met a guy 2 weeks ago...had an awsome weekend that we spent pretty much the entire time together, up until his kids came for 2 weeks and my kids come back this week. Since then he has texted every day (sometimes he initiates..sometimes me)..but more like "what are you doing" or "lol" ect..nothing cute or flirty. I even have tried texting "hey sexy"..ect to see if he will flirt and nothing..??

I like this guy but his divorce is not final for another 2 months and I wonder how much interest is there. (His friends say he is into me, but he only texts...never calls...) I realize some of this might be due to the kids being here, but even his friends seemed kinda supprised that he has not made plans to maybe watch a movie after they are in bed, or at least actually call. (He lives with 2 other marines so there are always people at his house hanging out..so I wouldn't stick out to his kids.) I suggested this via text and he said maybe Sunday..then sunday came and went with no invite...so I am not sure where that is going..

So last night I am at the local bar, with the bartender that is one of his friends. Another one of her guy friends comes in and we get to talking. (I had talked to him before) End up talking from 8PM to 12:30 about a lot of stuff. He asks me if i have a BF and I say no (because 4 days of hanging and 8 days of texting does not a boyfrined make). At the end of the night he gives me his number and says he wants to do something so give him a call.

Now I am not dating guy A (but we have slept together), so
1. is it "wrong" to go out to a movie with guy B?
2. Do you make it known you are seeing other people or just not say anything unless it is brought up? Guy A and I had one drunk night convo where he said "so I guess we are kinda dating" but never a "are we exclusive talk. I would not call myself his girlfriend by anymeans at this time.
3. The 3rd issue is the fact that being we all hang at the same place, (both guys are friends with the same female bartender) from a guys perspective what would you think if you were guy A or B and the girl was going on this date? (And before anyone goes there, I am not going to be sleeping with guy A and B if I go out on this date...if I end up liking B I would break off with A...) I don't think guy A and B really know each other since A is a Marine and B is Army.. but they have mutual bar friends.

I have never been one to date more then one guy at a time, so I am a little lost on the "rules" behind this or if it is just the wrong thing to do..?

So any of you ever been in this situation where a girl your seeing is seeing other people at the begining?

Well don't you think guy A is under the impression that you are interested in being serious....hence sleeping with him, etc? Was there anything mentioned by him that he wants to keep it casual? or isn't ready for a relationship? I think you owe it to him that you are out dating. Put yourself in his place.....how would you feel? Wouldn't you want to know? So now it's up to you to do whatever....thought I would just put some of it into perspective for you.

If you told guy A that you 2 are dating exclusively, then it would be bad to date guy B. Otherwise, go for it, and next time you see guy A tell him you are dating other people, just to be honest and look good.