I recently discovered that my girlfriend of three years has been cheating on me. To make matters worse, I found out in a pretty terrible way: I came home early one day to find her in bed with someone else. It was a crushing moment.

We lived together and have been co-parenting my dog, Max, for the past two years. Max is incredibly attached to both of us, but I've always been the primary caregiver. I take him to the vet, buy his food, and make sure he gets his daily exercise.

After confronting her, I told her that the relationship was over and she needed to move out. She was apologetic and asked if we could at least share custody of Max, given how attached she is to him and how much he means to her.

Here's where I might be the jerk: I flatly refused. I told her that Max would be staying with me full-time and that she wouldn't be seeing him again. She accused me of using Max as a pawn to hurt her, but from my perspective, I'm just trying to maintain stability for my dog and myself after a deeply hurtful betrayal.

AITA for refusing to share custody of our dog after catching my girlfriend cheating?