when a man is tired, bored, normally in the morning at his desk, while riding in the car, train or the bus, where he gets so relaxed that he pops a gigantic stiffy that he needs to hide and attempt to get rid of before he needs to stand up.
cures for sleepy boners include thinking about old people, saggy beef curtains, and imagining the sickest person you can think of naked.
When my train stop came up, I had to carry my messenger bag in the front because I could not get rid of my sleepy boner in time. I hope no one runs into it.
When wearing scrubs, the freedom can excite the junk into a boner, though not an angry one. Discovered at wilford hall medical center.
Dude, I was working the other night, and I got so relaxed / tired, I sprouted a hella sleepy boner.