Threesome Disagreement😢

My boyfriend and I have been together for 2 years. I’ve recently been interested in experimenting with a threesome. I have no interest in girls and I’d HATE sharing my mans dick, so I’d have to have a boy join us. My boyfriend is not into guys at all and he’d hate to share me. We agreed not to have one, but is it bad that I mentally picked a guy out? Is it bad that I sometimes daydream about it??

Edit: I 100% understand where he’s coming from and I’m not holding a grudge or getting mad at him. It’s OUR sex life, we should both have a say in what happens.