There's no problem with that. I know tons of adults who keep their stuffed animals. We are now living in a world where the things that used to make you seem "dorky" and "immature" in the 90s and 2000s are now socially acceptable. Think about it:They now make adult cartoons, adult stuffed animals/action figures, adult superhero comics, adult video games, adult puppet shows, adult coloring books, adult animated movies, and so on.