Ellen Degeneres challenged the duo to one of her favorite games.

Faith Hill and Tim McGraw perform on stage at the Rod Laver Arena on March 20 2012, in Melbourne, Australia.
Martin Philbey / Getty Images

After 20 years of marriage, it's safe to say that Faith Hill and Tim McGraw know each other pretty well. But, just to make sure, Ellen DeGeneres challenged the longtime couple to one of her favorite games: Never Have I Ever.

During a recent appearance on her show, DeGeneres handed each of the stars a paddle. On one side the paddles read "I Have" and on the other, "I Haven't." The playful host then asked them a series of awkward questions about their relationship, like whether or not they ever use each other's toothbrushes (they do…a lot) and if they've ever sent a nude selfie (neither have).

Aside from a few giggles, the country singers handled each question with ease, until DeGeneres dropped a bomb that knocked McGraw over, quite literally.

"Never have I ever waxed my partner?" the host asked with a straight face.

"What?" Hill asked.

"Waxed your partner," DeGeneres repeated, as McGraw was so overcome with laughter that he buried his face into the couch.

"I have never but I'm gonna try!" Hill replied after she collected herself.

So that answers that!