As a rule I never expect an extra, I'm paying for an agreed service for an agreed length of time.
Ignoring the odd couple of minutes overrun, from memory there has only been once where a meeting overran by a significant amount of time. We'd pretty much come to the end of the normal meeting time, and were just laying on the bed chatting about this that and everything, till it was time to get dressed and leave. She made some comment about she loved the sex part of escorting, but missed the post fuck cuddle you got in a relationship.
So I gave her a cuddle as we carried on chatting. She cuddled in really close, and after a few moments her hand went down and started to play with my cock again. I pointed out that I expected my time was up, and she just said, yeah but this is nice. So onto round two, which finished fairly quickly when her phone rang and it was a friend she'd agreed to meet up with and was now late. Our 1 hour meeting had gone on for about 2 1/2 hrs. I felt really bad, I didn't have any extra cash, but offered to pay for her time. She wasn't having any of it. Was going to give her extra cash at our next meeting.
Our next meeting she called off, and then when I contacted her again to arrange another meeting, she told me she was now in a relationship, and had a full time job, so was calling the escorting off. I wished her all the best, and that was the last I ever heard of her.