Paul Hunt, from Somerset, got sent the letter from his son’s teacher questioning the NSFW name his 10-year-old son had given to his imaginary friend.
Hunt shared a photo of the note on Twitter on 7 February.
It read: “[Your son] and a few of his friends often make up characters, give them amusing name and then have exciting adventures at playtimes.
“It has come to our attention that one of the characters has the name ‘Wildo the Dildo’ and this has, I’m sure you can understand, raised some concerns.”
The note from the teacher explained it was not a “behaviour letter as such”, but something they wanted the dad to discuss with their son.
They encouraged the “imaginative and creative” pastime of having imaginary friends, but felt the name was “inappropriate”.
The letter continued: “On further discussion, none of the children said they knew what it meant, but were aware it was an inappropriate word to be using.
“One of the children said they picked up the word on the playground, so we will be following this up further and dealing with it accordingly.”
The dad was told the teacher would be happy to “discuss it further” if he wished.
Speaking to The Huffington Post UK on Thursday 9 February, Hunt said: “We haven’t sent a reply to the school.
“When we received the letter we struggled to keep a straight face in front of him but we managed it somehow.
“He genuinely had no idea what the word meant and was mortified when he found out it wasn’t appropriate.”
The tweet was retweeted nearly 4,000 times in two days.