Sam was not aware of Sal's drugging him up to get him in bed. Were that the case, Sam would have been pretty fucking exciting, seeing as how the man he's been pretty much in love with for years upon years wanted him back just as bad. But seeing as how that was not the case, Sam as still on a sexual and emotional see-saw. On the one hand, there he was, in bed with Sal. On the other, he was unsure if Sal had any recollection on the night, and if he did, if he would react weirdly toward Sam. It wasn't as if this were the first time this has happened, and the idea of Sal finding out and not harbouring similar feelings was just too much for Sam to even think about at the moment.
So he woke up with Sal's arm draped over him, doing his best not to make any sudden movements as Sal appeared to still be asleep. He could just continue to pretend to sleep, but he really had to take a piss. A night of drinking and drinking and more drinking has a tendency of leading to a full bladder. He gently moved Sal's arm, and slowly got out of bed and made his way over to the bathroom, the events of last night being more of a blur than anything. As he made his way back to the bed, he wondered whether it would be wise of getting back into bed, or if a better idea would be to put some clothes on and go downstairs. He ran his fingers through his hair and after a few seconds of deliberation, decided to get back into bed. He could always blame it on a bad hangover.