Responses
She did say Antropomorphs don't have the same concept of marriage as humans. They get together with whoever they fancy and call it marriage, I bet the 5 dads have other spouses as well.
That's why, besides still being a Kindergartener, MC can't see any problem with her marrying the ML and the original FL later marring the ML as well.

Can we go back a couple of seconds, what do you mean that YOU HAVE FIVE DADS?!!!