My boyfriend is mad that I went to the gym alone, am I in the wrong?

So we’ve always went to the gym together. He has been to the gym alone multiple times in the past when I wasn’t in the mood to go but he gets annoyed when I still end up going alone when he doesn’t want to go. I don’t think that’s fair tbh. He even told me that I can go alone if I want to since he just wants to take the day off but when I actually went, he seems pissed… I feel bad now. He pays for my gym membership, I used to pay for his last year (we kinda take turns) and going alone kinda makes me feel guilty for some reason? Am I in the wrong here?

My boyfriend is mad that I went to the gym alone, am I in the wrong?
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