It's a really difficult question to answer because I can't speak for all SP's. I really varies depending on a lot of things, the Sp's personality being one of them.
There are some Sp's who have no problem whatsoever being completely honest and telling their client their breath smells. I envy them lol
These are Sp's who will also tell clients other parts of the body smell and instruct them to go take shower I they haven't done so already (some people manage to come out of the shower still not smelling fresh everywhere, I'm not sure how that happens but it does. Possibly the same applies to Sp's, I'm not singling out clients).
Honestly this is a skill that is so important in this line of work. I'd say it is important in life in general and most lines of work.
However it is not an easy thing to do for everyone. Many of us are worried about hurting someone's feelings. We have unfortunately been taught that we are supposed to be nice, not too assertive. Being nice is both a necessity in our line of work (an asset) and a problematic thing.
I used to have a lot of difficulty setting clear boundaries and having them respected. It was very difficult to say anything that might be negative or too assertive because I was unable to get passed the idea that I had to please, be docile not difficult and not 'mean' or hurt someone's feelings. It is not fun in certain situations and I envied my sp friends who were telling me about the way they had handled this or that situation. I didn't know how to be that way. You end up frustrated, resentful and taken advantage of in some circumstances.
I don't think it's all that uncommon.
I am not sure exactly why, maybe experience, age, and just being fed up and unwilling to put up with certain things but I have been able to improve this so much in recent months. Sometimes I impress myself lol The limit is there now. Crossing it is not acceptable and I say so. It's no perfect but I just don't stay quiet when I feel something is not right, someone is not respecting boundaries or other circumstances.
TLDR;
HOWEVER I am still not at the point where I am able to tell someone things like their breath is bad or body odor is unpleasant and they should go shower. The inevitable result is that I am not going to be inclined to give the same service level they would receive if they were fresh. It is their responsibility and if they are not taking it seriously, then even if I feel it's unfortunate for them, honestly I feel I'm 100% justified. I'm not a robot.
I have told clients that I was not enjoying certain kissing techniques mentioned above (pushing their head and putting the whole weight on me, or being to aggressive, even for drooling into my mouth. I've not really been able to tell someone about their breath but I'm going to make it a goal to do it. Sometimes saying this makes a difference, other times it changes nothing.
What I would suggest is that you first make sure to do all that you can to make sure you are fresh. Carry a toothbrush and mouthwash, use it before the appointment. Pop a gum in for good measure. And if there is every a situation like this, BRING IT UP calmly at the time. Ask her if there is a problem with your breath, your technique or anything else you could fix. If asked, it's much easier for her to say these things.
The last thing I do before I meet someone is brush my teeth and use mouthwash. Just to be sure. We should all b doing this. Especially if the sp has mouthwash available for you.
Unrelated to kissing but wash your balls thoroughly, also under because it sweats. Same with your dick. And if you are uncut, for the love of god, Peel back the skin and soap it up (use mild, unscented soap - avoid heavily perfumed soaps or bodywash. Just as it does to women's vagina's, they actually do more harm than good in the long run. Stick to unscented ivory or dove type soaps)!
Not wanting to be crude but that's the things we should all do.
Oh and use a wet nap or face cloth to clean it if you go pee mid session