Again, I like the idea, but the punchline doens't quite make. The first panel definitely sets us up for something sneaky, but just saying the word "semen" isn't really sneaky. I think there are two things you can do with this.
Have blue say something actually sneaky, like "I heard that when people come here, they semen cunt fall blow job losses of 69% at an anal-ized rate." (It's not perfect, but hopefully you get the idea.)
The other thing you can do is to have the geek react in some way that's amusing, like, "Sneaky, but do you really find semen erotic?" Or "Oh. I see your point."
Sorry if I seem to be overly analytical, but, well, that's kind of what I do here.
---
peddling the funny around since 09/24/2002