Busting your friends?

At the MGM this weekend and I just sat down with a friend of mine who is an extremely good player.

We don't cheat, we don't collude, but we do try to stay out of eachothers way. It's bad for the game if we play strong against eachother + there were more than enough donks @ the table to take money from.

Under the gun I post to enter the game (bad strategy but I wanted to make it look like I had no idea how to play). 2-5 blind $500 no limit game @ the MGM (great room BTW... check it out).

I pick up AA under the gun in my post (amazing) and advertise the fact that I'm trying to get my post back, raise to $30.

One caller, my buddy in the BB makes it $100.00 I know my friend will do this with exactly three hands AA, KK, or QQ. I call hoping to get the other caller to come in and play. Other caller folds... and I "waive off my buddy with my eyes"

He checks to me on the flop... I bet $150 and he thinks about it for a long time.

He fold his hand... tells me later he had KK and that I should have busted him for all his money.

What are your thoughts...

keep in mind we don't really have a standing agreement, but we do try to stay out of eachother's way with drawing/speculative hands.

Should I have just busted him in this situation?