I saw Mommy kissin' 
Santa Clausunderneath the mistletoe last night.
She didn't see me creepdown the stairs to have a peep;
She thought that 
I was tucked upin my bedroom fast asleep.
Then, I saw 
Mommy tickle 
Santa Clausunderneath 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 Clausunderneath his beard so snowy white;
Oh, what a laugh it would have been
If Daddy had only seen
Mommy kissin' 
Santa Claus last night.
Johnny Marks, 1949