Did I missunderstand it? (TW: brief mention of unwanted NSFW topic)

Hi everyone, sorry for intruding on your space. I am not very educated on age regression and am looking for some perspective from people who understand it. I apologize in advance if this isn't the right place for this!

​I (24, NB) met someone (22, M) online recently to make friends. We hit it off, and he started venting about feeling isolated in a new country and missing his mom.

​He asked for a hug, which escalated to him asking to roleplay where I "babied" him and acted as a "mommy" figure. I asked if this was like age regression (again, I'm wasn't really sure), and he said, "Maybe ig, it just makes me feel small and cared for." Wanting to be supportive, I agreed to a brief SFW scene where I asked about his day and told him to get some sleep. Afterward, he unexpectedly confessed that he had a physical/NSFW "reaction" to the roleplay. That unsettled me, as I have this mental image that age regression is completely non-sexual. I told him I couldn't continue doing it.

​I'm completely stepping away from the situation, but I feel out of the loop and want to learn:

​Is a physical/sexual reaction normal or common in age regression?

​Does this sound like genuine regression?

I feel bad for maybe being insensitive (?) as I'm not at all fond of judging people by what makes them cope or feel safe and that's why I'm trying to learn.