wow always amazes me how quickly peple tell someone to "get out" or to "dump him".
I agree with vvv, tackling your df while he was drunk was perhaps not the best move. Alcohol does highten one's emotions somewhat, and invariably it is not easy to reason with someone while they are under the influence.
If he does this sort of thing regularly then you should sit him down and have a talk while you are both sobour and discuss your fears about the relationship. But it needs to be done while you are both sobour/capable of having a rassional discussion. If he doesn't do this sort of thing regularly then I would still talk to him and say that it did upset you, esp the other woman, but maybe you can come to a compromise about him maybe not telling you when he will be back. if he doesn't tell you, then you won't have an expectation, as long as he doesn't regularly stay out until 4/5 in the morning.
When I had been living with my now dh for six months, he went out to a leaving do at work, he promised he would meet me from work at 7:00, but when I came out of work he wasn't there. I figured he was in the pub but when I got home I discovered him in bed, so smashed that he could bearly talk to me. I was absolutely fuming and told him in no uncertain terms that I disliked the person he was, that I figured he must have a drink problem ... etc etc. emotions ran high. It turned out he'd been drinking champagne with some IT contractors and between 5 of them they had drunk 8 bottles at 35 quid a pop. I was not impressed. But he has never done it since - it was a one off.
I guess what I'm trying to say is, one drunken night out is not grounds to end a relationship, if a relationship is worth ending over that, then maybe it wasn't that stable in the first place. Talk to him.