<human>: Can you summarize the given text in a few sentences?

The back story to this is that my SO [21M] and I [19F] have been together two and half years and have already talked about how we want to get married after I get out of medical school in a few years. Just because I want to be able to dedicate myself and not be in school as a newly wed. So talking about marriage is normal for us. 

The story itself occurred recently while we were at this little flea market and during the wandering I started getting the nesting vibes from planning all the stuff I would have put in a house and such. The epitome hit when we found this wall of vintage rings and I mused about an idea I had of getting a tattooed ring underneath your wedding band so that even if you lost the material one, the sentiment was still there. He has never really personally wanted a tattoo like I have so I wasn't going to be hurt if he flinched at the idea of a tattoo but instead he said "I don't like the idea of having something symbolizing the marriage that permanently on me, because what happens if we get a divorce? It'd be awkward." It threw me off because I had expressed my feelings about not believing in divorce multiple times (personal beliefs, I don't look down on those who are divorced) and he had never disagreed with me. So I had made the assumption he agreed with me. I expressed that and we got into an argument because he said I should have known he would have reservations because both our parents are divorced. The argument didn't end anywhere near constructively and I feel weird now. 

I really hate the idea that he is already making plans for a potential divorce and that our ideas for marriage have suddenly proven different. It makes me a lot less excited about talking about marriage stuff too because I don't feel like he is 100% there on all the plans now. 

Should I talk about this to him or am I just overreacting about this hesitancy?
<bot>: SO made an unexpected comment about his ideas on marriage that I'm uncomfortable with because it makes me think he is already making plans to reduce the impact of a potential divorce.