This Thursday night, wear your best Grandma bra, cause Blake Shelton is collecting them!

Somebody threw a huge white bra at Blake Shelton while he was performing on Saturday in Fargo, North Dakota.  It landed on the neck of his guitar and hung there.  He glanced at it but didn't touch it.

Here's the video - the girl who posted wants us all to know to know that it's not her bra!

So, get yourself ready with a large white bra to throw onstage on Thursday night at the TUC! And tune in to tomorrow morning to The Sean and Bethany Show to win tickets!