if i have more than a couple of beers, its hard for me to get there sometimes. like the other night, we were drinking and she got all horny on me and i pulled it off pretty good (only 2 beers into it) that time but there was times where i couldnt.
in short, yes, it does affect you. how much you had, what u had, and just the luck of the draw all affects whether youll pull it off ok. if i plan on having sex or think it might happen, i really try not to drink, maybe just smoke or something. or just drink really slow, because every time i just start pounding them, sex comes up. sex > beer.