To have an erection.
Some women make me downstairs happy.
A place where people keep weapons
My flamethrower is in my downstairs attic.
When you perform cunnilingus on a lovely lady. Maybe she's not so lovely. You do what you want with whom you want.
What do you say you put on that beret and put my baguette in your mouth while I go downstairs French. Don't worry about being all Marcel Marceau. My mom won't be home for another half hour.
A term for when a roommate refuses to go to bed and instead stays up all night complaining about homework. The observing roommate typically resides in a lofted bed.
Roommate 1: Rehhh, I hate physics!
Roommate 2: Dude, I'm trying to get some sleep. Quit being the elf downstairs.
Performing Oral sex on a woman
I didn't screw her, but i did get some dinner downstairs
fingering a girls vagina (downstairs) inside her pants (insidies)
Boy: How about some downstairs insidies?
Girl: I'd love to.
*Girl unzips pants*
A veritable mane of unruly pubic hair, often, nay, always accompanied by a massive overgrowth of ferocious facial hair. May be inhabited by various species of wildlife including: crabs, sabertooth crotch crickets, lice, fleas, small feral cats and the mythical crabacus. The downstairs beard, if left unchecked, will grow together with the upstairs beard creating one mammoth superbeard which will then slowly begin to digest it's host creature and become a sentient being.
Dude 1: "Dude! Why do you keep scratching your nuts? Knock it off!"
Dude 2: "Sorry, I've got something crawling around in my downstairs beard!"