Is it weird to fold another man's underwear?

READ THE WHOLE THING lol

I recently started babysitting for my husband's best friend and his wife. The other day, as his wife was leaving for work, she's apologizing for the house being such a mess and talking about how she hasn't had the time to do anything and the laundry in basket has been sitting there for almost a week. So I cleaned the house for her and folded the laundry. I guess my husband's friend was telling him about it and mentioned that I even folded his underwear. My husband started acting weird about that and told me he didn't like me folding another man's underwear (kind of in an uncomfortable, but joking manner).

For the last 8 years, I had been babysitting for another family up until the mom lost her job due to covid. I had always done most of their housework and laundry, so I always folded the dad's underwear.

So when my husband told me he didn't like me folding another man's underwear, I said, "I've been folding Mark's underwear for years". He just gave me a weird look and I was like, "you didn't know that? You knew I did all their housework and laundry....".

So now I'm asking you lol, is that so weird? He's not mad or anything, just kind of weirded out about it. I guess I just don't see underwear as a weird thing. Especially since it takes two folds and then I'm on to the next piece of clothing.