I saw Mommy kissin' Santa Claus underneath the mistletoe last night. She didn't see me creep down the stairs to have a peep; She thought that I was tucked up in my bedroom fast asleep. Then, I saw Mommy tickle Santa Claus underneath his beard so snowy white; Oh, what a laugh it would have been If Daddy had only seen Mommy kissin' Santa Claus last night. We know a secret, we got a little secret, yeah, yeah, nah nah nah! < instrumental break > Then, I saw Mommy tickle Santa Claus underneath his beard so snowy white; Oh, what a laugh it would have been If Daddy had only seen Mommy kissin' Santa Claus last night. Words and Music by Johnny Marks , 1949