Simon reckons their fetus days on X Factor created a lifelong bond and, now that they've been broken a bit by Zayn leaving, they will never really be the same. Okay, okay, that's maybe slightly over-dramatic, but Simon thinks the remaining members will still struggle a bit.
The good news? He also thinks they'll come out stronger because of it. Yaaas!
Simon told Extra, "Well, I don't think they'll ever be over it completely because they started off as a five piece, so they're always going to miss him" He added, "But, it happens."
Uncle Si did offer up this truth bomb: "You've got to dig deep and you rely on each other. In a weird way they kind of got stronger through it."
Judging by their recent shows, the 1D guys are kicking ass and having a great time. We have no doubt they'd rather have Zayn there too, but they're moving on like a class act.