Did I bring this on myself?

I've been trying to get my girlfriend to open up and talk dirty more during sex and boy did it backfire a bit. I've always been very comfortable and pretty open minded in our sex life. One night while she was on top riding me, I encouraged her to say whatever was on her mind. That's when size came up. She and I know I'm not the biggest guy lol, but l've never had any complaints before. She started describing how during our break she hooked up with this guy who had the biggest dick she'd ever seen. She said it was the best sex of her life, that he completely dominated her, pinned her down, and took full control and how she never knew how much she liked a dominant man. As she told me all this her hips moved faster and she got louder, moaning about how good it felt while she rode me until she finished.

Afterward I had so many questions because I didn't think that we would see anyone else during our break time.

Turns out she had been hooking up with this black guy multiple times. That she met at her work. My girlfriend works as a bartender. The guy is a customer and mutuals with her older sister too, and now both of them will make little comments and joke about her fucking him in his car and about his size in front of me even . Her sister even gave her a huge black dildo as a "joke." It's noticeably bigger than me. She uses it during sex with me occasionally and while she does she often talks about him how he felt inside her, the times they hooked up in his car, how he dominated her. It feels pretty emasculating.

I've tried hinting that it bothers me how much she brings him up. She just smiles, kisses me, and says it was one of the best she's had but that l'm one too. I can tell she's thinking about him the whole time, especially when she's using the toy.

Another thing that bothers me is the dildo itself. I leave for work earlier than her but usually get home first. I keep finding it left out on the bed, the coffee table, or her nightstand. A couple times maintenance has been in the apartment and I've come home to it sitting right out in the living room in plain view. That's been really embarrassing.

I'm not sure how to handle this. Any advice? Feel free to dm me