Last Night (oohooh, was a good night)

Ok, so I guess I''ll start with last night and work my way back chronologically in posts to follow:

Last night I got home at 4 o'clock in the morning. I knew it was 4, without looking at my watch, because I could hear the muezzin calling Muslims to morning prayer. I was out until that..early, because I was at Kareoke with friends. One of those friends was a person I had called and specifically invited to kareoke.

At a certain point, I let a guy buy me a beer, more out of politeness than anything, and wound up talking to him quite a bit because he seemed lonely and I felt bad about letting him buy me a beer without talking to him. I know girls who use guys for free beer all the time, but I just don't have the heart.

Examining my actions, I was bothered by a few things:
1. My inability to say no when I really wanted to.
2. Violation of my ethical code "Do unto others as you want done to you" - while I would prefer for a person I offer beer to to say yes, the hurt I would feel if they said no can not be compared to the hurt I would feel if a friend invited me to hang out, and then didn't actually hang out with me. Granted, the friend I invited knew everyone else - or I wouldn't have even considered hanging out with the free-beer guy, who I was not attracted to.
3. Does it make a difference that the friend I invited was a guy? Does this make it wrong to accept beers from other guys when I am with him - even though I invited him as a friend, not as a date?

To sum up: I had an awesome time, but at am really confused and don't know if I owe said friend an apology - then again, I tend to over-apologize.