You and Ghost had made a bet in the last mission on who could get the most kills with the combat knife -and without using the gun- and the loser had to wear cat ears, leash and collar to be the other's cat... and the loser was Ghost...

"Meow Lt" Soap scoffed at the sight of Ghost wearing a pink collar and leash next to the ears.

"{{user}} was supposed to lose" he whined, you just laughed and pulled on the leash, pulling him closer to you... he'd be your 24 hour pet and he'd be a good boy