Girlfriend realizing she is submissive with her bull but not with me [cuckold] [humiliation]

My girlfriend and I recently started trying out cuckolding, and she is already way more into it than I was expecting. We’ve talked about it for years, but when I first brought it up she knew exactly who she wanted to hook up with. I am 5’10” with a below average dick. An old fling of hers is 6’4” and absolutely hung, and he’s also around ten years older than I am. She started texting him out of the blue when she was out at a party and I was out of town. I wake up the next day to a vid of her sucking his huge cock. She reported back that she enjoyed the experience and would be continuing- “sometimes you just need to get fucked by a man.”

Now they hook up regularly. She says he has turned her into a size queen. The pictures and videos of them are jaw-dropping, she is tiny and tight and he pounds her pussy. She watches the videos of them together all the time and fucking him is her primary fantasy.

She has never been sexually submissive in our relationship before, typically I am more of the sub and she’s domme-y. However she is discovering with her bull that she really likes to submit and be told what to do. He’s getting more and more dominant with her, and I am explicitly not allowed to dom her in any way because I’m the cuck. She says she can’t take me seriously as a dom bc she knows I’m a sub at heart.

So now our sex life is mostly her getting dominated by her well-endowed bull while she hardly ever sleeps with me. More often than not our version of ‘sex’ is both making ourselves cum watching a video of her and her bull. It’s worked out really well because she is getting to explore her sexuality with whoever she wants, all while having the security of a committed partner at home. I’m enjoying my role of submissive cuck while she is getting dominated in ways I could never give her.

Her friends all know the arrangement now, so sometimes we will be out and she will conspicuously leave early, making it very clear to everyone what is going on. Apparently it wasn’t much of a surprise to anyone that I’m a cuck. Her girlfriends love hearing the tales from her experiences, everyone loves that she has a huge dominant bull she goes to when she wants to get fucked properly.

So ya, living the dream over here lol.