Is it weird if my straight guy friend jerks next to me?

[brandon]

I was over at my buddys house we were both drunk i was about to pass out. I noticed him jerking out next to me and looking at me when i wasnt looking. The weird part is i was watching a movie and he was laying between the tv and me. So he knew I was up cuz I can see him from the corner of my eye. Im not sure what that means for all i know hes straight? Do u think he has other intentions with me? He kept looking at me then rolling his head back and shutting his eyes and kept doing it over and over. He did keep it in his briefs so i dont know if it was a late night beating he had to do, or if he did it cuz i was present. He's a real good friend and i dont want to f*** anything up. Im kinda curious how can I reply to his actions