Participants in this year’s summer carnival  street parade in Rotterdam will have to show some restraint in their dance routines, the organisers have said.

Last year’s edition was marred by “vulgar” dance moves that have no place in the festival, Eva van der Vegt, director of Rotterdam Unlimited Zomercarnaval told broadcaster NOS.

“Bubbling” in particular, where dancers rub up against each other’s genitals, has been banned for being too provocative.

“This is a family event for everyone, including little children. And we want it to stay that way,” Van der Vegt said.

The organisation said it had received several complaints about offensive behaviour over the years.

Van der Vegt admitted the line between sexy and vulgar is a thin one. “You see two people dancing and it goes on forever and you think “what’s going on there?” It’s not as if shaking your bum wil land you in jail. We are just appealing to people’s sense of decency,” she said.

The city council has also banned supermarkets and local shops from selling cooled alcoholic drinks during the two-day festival because people are ignoring the ban on drinking alcohol in the streets. Police will be around to check on this in a “coaching manner”, local broadcaster Rijnmond said.

Vander Vegt said people who flout the new dancing rules will be warned and persistent dirty dancers may be banned from this or next year’s carnival, she said.

The Rotterdam Zomercarnaval takes place this weekend, on July 28 and 29.