The sexually explicit remarks were written on the side of the Cocker Clock at Stanley Park.
A bin was also been dumped in the park lake and glass bottles smashed around the bandstand in recent weeks.
And Elaine Smith, MBE, chairman of the Friends of Stanley Park and the Sailsbury Woodlands today hit out at those responsible.
She said: “The people who do these things are mindless idiots. They don’t see that the time, effort and money that has to be spent putting things right would be better spent improving things there for the general community.
“Their stupid actions cost us all in so many ways and should always be reported to the police immediately in the hope of stamping out this vandalism.”
Lancashire Police has a community beat manager dedicated to the park and regular patrols are carried out.
Blackpool Council today condemned the actions of anyone causing damage.
Coun Graham Cain, cabinet secretary for Blackpool Council, said: “It’s completely deplorable for people to be causing any form of anti-social behaviour in any of our parks.
“If there is any damage, graffiti or litter in a park then our staff have to go out to clean it up.
“But that’s not a real solution, as they are stretched enough as it is and instances like these ones put further pressure on their time.
“It sounds quite simple but all we ask is a little respect for the parks and the people who look after them.”