Bridgit Mendler & Shane Harper: 'Song for You' Performance - Watch Now!

Bridgit Mendler plays the keyboard while performing “Song for You” with co-star/boyfriend Shane Harper during an episode of Good Luck Charlie.

The 19-year-old actress/singer’s performance is scheduled to air on Sunday (December 12) at 7:30 p.m. during the “A Duncan Christmas” episode.

PHOTOS: Check out the latest pics of Bridgit Mendler

In this episode, Teddy (Mendler) takes Charlie (Mia Talerico) to see Santa Claus at Super Adventure Land, but when Santa decides to take a break right when it’s Charlie’s turn, Teddy takes matters into her own hands.

Meanwhile, Amy and Grandma Linda learn they are performing the same song at the family talent show.