I lived off campus when I went to college, but a few times I ended up over at a girl's (or guy's) dorm room and it was just matter of fact.
I remember one guy who would beg to suck my cock and when I finally agreed, he took me back to his place and with the lights on, he just sucked me for over an hour while his roommate just sat there on the computer doing a term paper. He did have some headphones on, but since the room was "L" shaped, he couldn't help but see us out of the corner of his eye. I was hoping to make eye contact with him (exhibitionism is such a turn on for me), but he just went about his business like I wasn't there.
A girl I would hook up with once in awhile had a "10" for a roommate and I was really hoping for a 3way, but her roommate would just excuse herself and go to the library or where ever. I'd even close my eyes and imagine it was her roommate sucking my cock because the girl I was fucking was what would be considered a "4 shot girl" as in you needed 4 shots of Jack Daniels to make her look good. Great fucking sex and a total freak (anal, fisting, rim jobs), but not the most attractive girl you would find.
Only other story was when I was in the Army and my roommate would bring back girls to the barracks (a two man room) and even with the lights off, I could see them fucking because his bed had a street light right outside the window and he never closed the curtain. He was a muscular black guy with 8" or 9" that was average in girth. We'd jack off together watching porn sometimes, but he never wanted to go any further. I know he really wanted to because he'd really get off on watching me cum (I was 19 and could shoot Peter North sized loads at that time). He would cum like crazy watching me shoot all over myself. But back to the girls. A few were black girls and one or two white ones. The black girls were no problem, but the white ones had to be snuck in because it was Louisiana in the early 80's and not really something that would be accepted even in the 80's. One black girl he'd bring over was also a girl I would fuck on the side (without him knowing) and she said he would never eat her pussy or do anything other than straight fuck. I know he ate pussy because he'd eat the white girls he brought over, but never the black ones. Sometimes I'd jack off while watching in the dark (my side of the room was very dark) or I'd slowly stroke my cock and hold off cumming till she was gone. Then we'd pop in a VHS tape and I'd blast a huge load for him.
(damn, I made myself so fucking hard remembering all of the good times I had, shit!)