Amelia: "I'm sending you a listing of a fixer-upper. It needs a lot of work but the price is good and so is the location."
Bob (upon receiving the listing): "You've gotta be kidding me, Amelia. Looks more like a fixer-downer to me. Take another gander."
A boner downer is a term which is used to express not only the frustration of being turned off, but also the actuality of losing a boner. A boner downer may occur when something someone says turns your boner or any potential boner limp instantly.
Guy 1: Man you should have been in the child development studies class yesterday! There was this smokin' hot babe in tight yoga pants and you could see right through them!
Guy 2: Shit I can't believe I missed that, I slept through my alarm.
Guy 1: Yeah she was so hot...but then the speaker started talking about teen pregnancy and it was a total boner downer!
This person usually will have an even story or event worse than the situation you are or have experienced. The opposite of a "one-upper"
I was telling Maria about how I wrecked my motorcyle last week and Crystal, the one-downer, proceded to explain how she was in an accident and lost her leg, punctured a lung and apparenly the hospital food was shiite and came back to life as hedgehog..