TL;DR version: don't praise someone after failing a mercenaries game.
I was playing mercenaries, Urban Chaos with this guy, and we got the combo to 100 before losing it. Pretty typical really, except that he praises me afterwards. So I praised him back a few times in retaliation. Next game, we got till 100 before he dies. Then he has the nerve to "good work" me next game. These ********s always think it's my fault no matter what happens. I spent the entire game praising him up until the combo reached 30, where I died because my camera was always focused on him, and I couldn't see anything.
He didn't learn his lesson, and good works me again at the start of the next match, so I spent the entire match "good working" and shouting "nice" at him again, except this time I was experienced. Whenever I melee'ed anything, I'd take advantage of the invincibility frames to good work him. I'd spam good works while I was walking. I'd good work him while dodging that Napad that was chasing me since the combo reached 17. And I'd sneak in a few good works after killing something.
Before long, the combo count was 100 and it was getting pretty hectic. I was good working him while countering bloodshots when he goes into dying. This was the moment I was waiting for. All 100 combo lead up to this moment where I good work him as he's dying. Unfortunately, to my surprise, my only options were yes, and no. WTF? Just as I was in shock from this turn of event, a zombie grabs me and puts me into dying. NOOOOOOOOOOOOOO! At my last moment, I crawled desperately, trying to stay alive until he dies first.
But I still died. He didn't good work me next game though. And then we got a 150 combo and a score of 1.3 mill. I left the game and sent him a message afterwards: "good work." His reply? "Nice."