Ariana Grande is going to have a HUGE special guest at Coachella this weekend... TMZ exclusively learned that *NSYNC will be joining her on stage during her headlining set on Sunday night!
Sources say the group is planning something with Ariana onstage, but no details have leaked yet.
Ariana might've hinted at this recently when she posted an old video of her in the crowd at an *NSYNC concert, singing along in her mother's arms. Some are also wondering if they'll perform Ariana's hit song, "Break Up With Your Girlfriend" together, because it samples an old *NSYNC hit.
The only downside of this surprise? Justin Timberlake will reportedly NOT be involved.