Boner shrinker

When you're really excited about something that is gonna happen and someone else says something negative to ruin your excitement.

Tom " o man Zack! I can't wait to see my girlfriend tonight!
Zack " yeah bro.. too bad she died today and you didn't hear about it until just now!
O BURN!!!!!!!!! That's a real Boner shrinker huh? Wow..Heh I'm so glad MY girlfriend is still alive and not dead like yours"

boner shrinker

When someone in your group is no fun and tries to ruin the fun for the group.

We were at the strip club and Norman was being such a boner shrinker and wouldn't stop talking about his problems.