DH and DD are listed under friends and family on my MDE account. DH wants to use the app while we are in the park. If he creates his own MDE account now will that mess up our tickets, reservations, or FP+ selections? Wondering if I should just have him use my log in to be on the safe side.
It shouldn't. If he creates his own MDE account, you would need to invite him from your account and then all his plans will merge with his new account once he accepts the invite (but should remain intact).