I'm in college. I used to sleep naked, but I decided to sleep in my underwear. However, when I get up I have erections, and I have a roommate. So how do I cover it up?
You have two choices. You get up and act as if it is nothing unusual, which is the truth. Or, you can stay in bed a few minutes and wait for the erection to go down.
All males have erections when they first wake up. Your roommate is in the same boat as you. He might tease you, but since he experiences the same thing, it isn't something he can make a big deal out of without implicating himself. The best response to teasing about a normal fact of life, is to treat it as if it was a compliment. So if he mentions your erection, just say it was a nice dream or that it is good to know it is still working.