Alcohol was blamed by a man who verbally abused police officers while on a night out in Grantham.
Ben Jameson of Brendon Close, Gonerby Hill Foot, admitted committing a public order offence in Grantham town centre on May 26.
The court heard Jameson had been told by officers to get into a taxi and leave the town centre because he had drunk too much and was being argumentative.
Eventually Jameson did get into a taxi but then began making lewd gestures to police officers.
Daniel Pietryka, prosecuting, said: “It was the “come on” gesture, according to the officers, and shouting to them “you f***ing c***s”.
Police officers then approached the taxi and arrested Jameson.
Jameson, defending himself, said: “I think it was all down to too much alcohol in my system. It was not like me to behave like that, especially that kind of language.
“I would just like to apologise.”
Jameson, 22, was fined £100, a victim surcharge of £20 and costs of £85.