Deleted by author-gctid8359

I have had it before too and it just seemed to go away by itself. Your groin will get stronger as you go on, not to say it wont happen again.Everything in moderation.

In additiion to regular Kegel and simple pre-session stretching exercises, don't overlook body hydration before and during a session. I drink a half bottle (small) of Gatorade during my pre-session shower and keep the bottle on my nightstand to sip on during the session.
My doc emphasizes that as we age we generate less sense of thirst to signal dehydration so must "force fluids" throughout the day and particularly during any event that could result in "Delayed Onset Muscle Soreness" (DOMS). See: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1323290/.
hope this helps .... rook