I dated someone for 7 months. Exclusive but not bf/gf. Did all the bf/gf things. When asked to become bf/gf he shuts it down. We’ve said I love you to each other. I broke it off recently and told him if he’s ever changed his mind about being in a relationship to come back around if I’m single. It felt irresponsible to keep investing in something he already shut down the idea of. Is he being petty about the official title?
I agree he's being unnecessarily difficult over something insignificant. He sounds uneasy at labeling the relationship because that will make what you're doing real and more permanent. If he knows it's something important to you and won't budge, he's not ready to commit. He wants to keep that window of opportunity open a little bit longer. Welp, he got what he wanted. That window is wide open now.
I can't tell if you guys are exclusive as in you've both said you're not dating/sleeping with anyone else OR if you've promised to only be with each other.. If it's the former, then I suspect your guy either wants to sleep with other people or already has. If it's the latter, he's just being ridiculous.
That said, I would love to examine why the title of boyfriend/girlfriend is so important to you if the relationship is progressing at a healthy and promising pace. Is it because it's a hassle to introduce him or have to constantly explain what you guys are? Or is it because you seek the social proof that comes with saying you have a boyfriend?
Mind you, there's no wrong answer here. Society has made single women feel inadequate for decades if not longer. I get the desire to be able to claim someone as your boyfriend. There's a validation bestowed upon women who can say they have a partner, one un-coupled women are not given. Trust me. I get it. Sometimes I think the only reason we pursue relationships at all is because we're told that's what we're supposed to want. If we could come out from under the shround of shame society places over us for being unmarried, we'd probably make much smarter choices when it came to our romantic relationships.
I don't think you should try to fix things with this guy. His inability (or refusal) to label the relationship definitely feels like a sign he's not ready to commit. You did the right thing by ending things. There's no use investing time in a dead-end relationship.