tuc biscuit said:
I can see they guy whenever, wherever.
Will he talk with you or be civil?
If you can act as if you are like "hey man, this is stupid, let's just get back to being ass wranglers again - come on, let me buy you a beer/lunch/dinner or whatever..."
Then once you have access to his food or drink, there are a world of possibilities. Ideally you wouldn't need this and instead would be at his place, with him there or not wouldn't matter.
But I suppose to be there with him at a resteraunt when he shits his pants might be even better.
I was going to suggest Visine, but that can too easily kill him and you don't want to do that... I'm assuming. It does it in a really painful and hideous way - even if it doesn't kill him, it seems a bit rash.
The other option would be various sugars - especially dextrose in drinks are very sweet, but they are also extrem laxitives.
I used to tell people of a blue dye that you can get in crystals that stains the skin well - but then it showed up in some kids movie and that makes it that much cheezier to actually use after that.
You could slip him a roofie and then anally violate him - that is always an option even if he wasn't a dick.