Staff at a north west London called the police on Colm Doherty - all because he sang happy birthday to his eight year old daughter!
Colm, 47, and his wife, Marie, 49, had attempted to book a party at the venue but were told that there wasn't enough space.
However, the couple decided to visit it anyway and, when they arrived, they saw two party booths which were empty.
Despite the party of 20 children and six adults being seated, a female member of staff later said they couldn't have a cake - which they'd brought themselves, under the centre's policy - or sing happy birthday because they had not booked it.
Colm refused to listen, stating that he didn't want to "put a downer" on his daughter, Cara's birthday.
He said: "When the cake came out you could sense a bit of nervous tension among the staff, and one particular lady came storming down and told us that we could not sign and to put the cake away."
When he stood between the woman and the children to shield them from getting upset, they called the police.
However, the manager of the centre said: "You don't celebrate a birthday party on our premises unless it is the package you obtain.
"There were four other groups and we did not want them to see that people can just come in and celebrate a birthday without respecting our policy."
Police confirmed that they were contacted but that no formal action was taken.