I am very quick to refuse to kiss if they have rank teeth and breath. I firstly try to avoid it by going 'down there', and then hoping that they don't attempt to kiss, but if they do then I quote medical facts at the about germs exchanged during kissing (if they question me as to why I wont kiss) how the mouth is the second dirtiest place in the body (first being your nose!), etc, then hope they get the message. Sometimes I've had to be quite brutally honest, maybe to soften the blow just strike up a conversation about when/if the last time they've been to a dentist. If they've been arsy with me I've gone on about how us Brits could learn a lot form the Americans when it comes to oral hygiene! It's a tricky one, and it really depends on the individual client as to how you approach it. Never say 'sorry' for not being able to kiss them if it's their fault that they've turned up with a skanky mouth, sorry is an admission of guilt, and you're not the guilty one here! Just tell them in a direct matter of fact kind of way, then quickly move on.
I used to never French kiss, but I did kiss, and so many clients would make remarks about how I do owo and cim, I'd think bugger off I can do what I like! Kissing feels a lot more intimate than the other things we do, and only us escorts seem to understand that! X