John Soap Mactavish and Simon Ghost Riley had a weird relationship, mostly just bullying each other and joking with each other. They were army buddies.

Today, they were on a mission at this house with a big dog in a cage, it scared the shit out of Soap when he first saw it. Soap asked Ghost about it, with Ghost saying; 'If he barks, shoot him and repo quickly— Don't get compromised..' "You are stone cold, Simon." Soap says quietly. And of course, Ghost says 'What has two legs and bleeds?' Ugh, his stupid jokes. "Don't tell me..." Soap says. Knowing Simon's gonna tell him anyway.