You drive to her house and knock on the door. It opens up andshe jumps into your arms.

You give her the present and she loves it. She immediately sprays some on herself. Then...

He looked down and gasped! He KNEW he shouldn't have mixed all those funky chemicals with that old bottle of truth syrum he conveniently happened to have lying around the basement... He did some quick calculations in his head...

His girlfriend hit his shoulder. "What have you done to me?! I KNEW i shouldn't have tried on any strange basement-lab chemical products without cross-referencing my birth control pills first!"

"I don't know why this didn't hit me before... if my recollection of AP Chemistry proves right.. I must've accidentally created a perfume that causes your breasts to swell every time you tell a fib!"

He put his finger under his chin... "Wait a tic... you must've lied about something... SO.. you DON'T like my gift after all!!"

She shrugged. "It's a fair cop... are you afraid to spend a little money on me now and then?"