If I'm doing an afternoon date I might mention the pool and that she can bring a suit if she wants to swim or hang out. Note...all my afternoon dates have been with girls from CIB and Cindy's. No one has ever taken me up on it. I think for 4 reasons:
1. They don't want to be in the sun and get their skin darker,
2. They don't want to get their hair wet,
3. They still have to work that night and need to go back to their room and get some more sleep and get ready for work.
4. They are sex workers and I'm just a customer for them. They don't really want to hang out after the job is done.
It would be different if your date was with a girl from TF or whatever and not full time pay for play. Or if it was a long long time date.
In Thailand I've found that almost all the ladies will take you up on going for a bite to eat either before or after fun in the room, but that's about the extent of extra curricular socializing I've experienced.
Totally different from Las Vegas. If you ask a stripper to hang out at your poolside cabana, 90% will take you up on it.