I bumped into a friend of mine the other day.
So i set him on fire.

Why did the spy cross the road?
He didn't, he 'never really was on your side'

What do you get when you cross the Ambassador with an Ubercharge?
Diplomatic Immunity.

How many Snipers does it take to screw in a lightbulb?
One, but try telling that to the other seven Snipers on your team.

Why can't the demoman be a forum moderator? Everything would be stickied!

What do you call a Demoman that was killed by a Postal Pummeler? Black Mail.

A spy walks into the enemy base, disguised as a soldier. He sees a medic, medi-gun outs and decides to try and get healed. He runs up and yells "medic".

The medic looks at him for under a second and yells "spy!". The Spy is confused by the lack of spy checking for the 3 seconds before a crit rocket gibs him.

The spy then respawns, comes back and finds the medic, his gun ready. This time disguised as a demo he tries again. Same thing.

He continues to try it, pyro, engie and spy. No matter what happens the medic only has to look at him and he knows he's a spy, no spy checking.

Eventually the spy goes up to him un-disguised and says "How'd you do that?"

The medic looks at him and says

"Turn around and I'll tell you"

So he turns round, not quite sure why.

"peekaboo" backstab

What do you call a Vintage Sandvich? Food poisoning.