well somewhat by accident today i took everyone's advice and had two separate 30 min punts an hour or so apart. i'd gone to see the first girl with money for an hour in my pocket but had only booked 30 mins (i hadn't seen her before so always book 30 mins with a view to extend on a first meeting).
anyway she wasn't what i hoped for from the aw pics so stuck to the 30 mins - pop 1 completed with sufficient time left for a bit of a massage.
got back to my car and checked aw - one of my back up regulars was available today so gave her a ring and arranged to go and see her when she was settled in. that second punt was great and went on for ages in many different positions
having that break in between really helped with stamina and enthusiasm
so that really was some good advice guys - thanks