Hot take: you have a right to do whatever you want, just as he has a right to not tolerate it.

If you want to be in a relationship with this guy, that apparently comes with some restrictions to tattoos and clothing that make him uncomfortable. You are under no obligation to follow that, but he also isn’t under any obligation to continue in a relationship where he feels his views on modesty are being ignored

Maybe I’m too old for this shit, but if I was wearing something or getting a tattoo that my significant other didn’t like/made them feel uncomfortable.. I just would stop/not do that… just how I feel, I’m sure I’ll get downvoted to the center of the earth, but I feel the same to some degree in a relationship with regards to wanting a girlfriend who dresses a tad more modestly