In A Longer session (3-4 hours) do most providers have a problem with doing it in the shower or jacuzzi?

What about overnight appointments? is it acceptable to as for sex in the shower or jacuzzi?

As it can take an hour to dry her hair and fix herself up afterwards.

As for the jacuzzi, she would need to be prepared with a silicone lube.  Water soluble does not work.  You would definitely need to let her know that the room has a jacuzzi.

I 2nd that Raegan... I won't do it either in the shower or jacuzzi... extremely uncomfortable

condoms are really hard to deal with in a watery environment.

Tell her before the appointment that you would like to play in the water and she'll prepare. Even if she isn't comfortable "doing it," she will probably be up for fooling around!

100% agree, painful as hell unless the right lube is used.  Showers are fine, but condoms will give you problems as the lube will fade.