Thanks, Dad! Boy accidentally wears a rude Christmas jumper to school.

With just days until Christmas, the festive spirit has well and truly taken hold.

And the ugly jumpers have come out.

But one American five-year-old was sent to school in what he and his parents thought was appropriate festive gear.

Until the boy’s teacher pointed out that the Santa on his jumper was urinating the words ‘Merry Christmas’.

Choosing to see the funny side, AngryHamzter uploaded the image to Imgur, writing: “Accidentally sent my son to school with his newly bought ugly Christmas sweater.

“Didn’t realize what Santa was doing until his kindergarten teacher pointed it out when I picked him up after school.”

Accidentally sent my son to school wearing his newly bought sweater. Didn't realize what Santa was doing until his kindergarten teacher pointed it out to me when I picked him up.

The adorable image has been viewed almost 5 million times and has attracted many pee-related comments.

“You can’t wear that when urine school apparently,” one person wrote.

“Urine trouble now,” said another.

And, of course: “Merry Pissmas.”