Even Hallmark says they shouldn't have messed with the lyrics of one classic Christmas tune.

It appears the marketing department at Hallmark needed to mess with Deck The Halls -- on their ornaments they changed a lyric that's been a double entendre for generations and set off a firestorm with customers.

The lyric "Don We Now Our 'Gay' Apparel was changed on an ornament line to read "Don We Now Our 'Fun' Apparel and thats when the fun stopped.

Immediately critics said Hallmark gave in to political correctness.

Hallmark announced the decision back in June, but only now are they seeing the backlash. 

They still sell sweaters with the traditional lyric however.