No, not because it's offensive.
Because in addition to being offensive it's a homophobic term.
If we can't insult and offend Chelsea fans without using homophobic slurs it's not only on the pitch we lack creativity.
It's really not that difficult to insult and offend people without using bigoted language.
It's not up to us to decide if it is homophobic though. That will be the courts decision. For that they would require context. Rent boy is in the dictionary and simply describes a young male prostitute. Context would be required. Tottenham fans were deemed not to be antisemetic for chanting yid army.
Would be interesting to see the court case though. The prosecution trying to prove that chelsea fans are young male prostitutes.