It’s legal to refuse service / refuse entry due to disruptive behaviour, which this may fall under - so long as you are not discriminating based on age, gender, race, religion etc.
Also, not everything that is a legal business practise in other fields is legal when it comes to sex work. It’s a criminal offence to induce someone to undertake sex work, so this might be a legal grey area or illegal (I’m not a lawyer) - depending on what exactly is (allegedly) going on.