Well, I might have heard a lot worse!
But maybe, I was unlucky (as usual).

Some do, I admit, and I have to say, "rub it in" and
and say, next time, rub it in, to reinforce it/criticism.
It occurred to me if he doesn't
like me that much... It does put you off, but
I heard snide comments.
Post-cum Moodiness? 

I'm OK so long as complaints/critique are not directed at me or the
premises/hotels I'm at, dirty, how cold, shower bad,
that will drive me insane!  It costed me much,
"learn to be nice or get out!"

Some men do seem to enjoy looking at your reaction.
They are paying and he thinks "let's entertain himself".
But I had seen a lot worse.  They act as if you don't count.
Some areas are nicer than others.

"You weren't my first choice, but I'm glad I came to see you,
instead, oh boy, you were a lot better
than I imagined!".   Some men don't say but he might secretly think.
Some say things to hide their lack of confidence/ pre-coital jittery feeling.
They are complex.  Even more complex than women sometimes!

Paying makes some men go weird, as I learned.
But if he said it in an unpleasant way, I cannot go thru it.
Take the half and return the rest.
But he said it out of social awkwardness (autism?) as
someone else commented,
that's ok.  Nobody is perfect.

Had one of these yesterday, a short notice booking.

After he arrived he told me that I was his "plan B" as the girl he really wanted to see cancelled on him.

I told him that's OK as he's client b, A is running late and will be he after your time is up.

That deflated him in more ways than one 

Well said 

@regieee '
"You weren't my first choice, but I'm glad I came to see you,'
That would not bother me either i would actually take that as a compliment. Its when the intention behind something is to hurt you that I will not stand for x