I agree with others. I guess you are either ok with it or you don’t. I don’t think it’s fair or reasonable to expect him to change and stop it. It’s personal choice. Personally I’d draw a line at little ponies. If you aren’t ok with it either, then time to end it. Just telling him to stop won’t work as he will just do it in secret.

I do encourage you to not share it with other people as it’s kind of his personal business