My size!
This is the type of prank you pull on someone while they're yawning. When you see someone yawning, you yell out 'My size!', meaning that the size of your dick takes that much space.
Example:
'Oh man, I'm pretty tired.
'Yea man, so am I. *yawns*.'
'MY SIZE!'
'Yea, you feel proud of yourself, fuckboy?'
'Oh man, I'm pretty tired.
'Yea man, so am I. *yawns*.'
'MY SIZE!'
'Yea, you feel proud of yourself, fuckboy?'