My boyfriend (M25) and I (F29) have been together for 5 years. We met 7 years ago working at a seasonal hotel together, and were good friends for 2 years before we got together.

At the hotel we both worked with a girl around our age, we will call her Tonya. It is worth noting that we all lived and worked together, so we were fairly tight-knit. Staff meals at this place were rarely fancy, but one night the chefs treated us to a restaurant meal. I reserved a confit duck for after my shift. When I got back to the staff room, Tonya was eating a plate of duck, and my duck was nowhere to be found. The name on the glad wrap had been ripped out. She never admitted to eating my duck despite several confrontations, but I know she did it. I basically caught her red handed. Call me petty but I have held a grudge over this ever since.

Anyway, my boyfriend was pretty good friends with Tonya. He says they never hooked up or had that kind of relationship and from what I saw of it I mostly believe him. It has now been 5 years since our time working at this place. My boyfriend and Tonya haven't kept in contact at all since they stopped working together.

Every now and again Tonya and the duck incident will come up somehow. I maintain that I dislike Tonya - yes, for the duck-stealing, but also for some other shady behaviour she exhibited throughout our time there. My boyfriend maintains that he still considers Tonya a friend and doesn't have an issue with her.

These conversations usually end up in a fight. I want my boyfriend to have my back and recognise that Tonya's actions were shitty. Instead I feel like he sticks up for her, despite it being 5 years since he has seen or talked to her. He says that he just cannot match the dislike I have for Tonya because they were friends and she never did anything to make him particularly dislike her. I feel like he should just say for my sake that Tonya is shitty, since it wouldn't affect their non-existent friendship anyway. I don't need him to dislike her as much as I do, I would just like it if he didn't actively stick up for her whenever this comes up. At this point it has almost become a meme in our relationship, but I'm not laughing.

AITH???