we just laugh it off and I call him a dirty old man and we go into round 2.

You probably know this, but leg cramps are most simply caused by using muscles that are out of shape, or dehydration.  Sooo, if you're out of shape, get more exercise for the muscles affected.  
To avoid dehydration, make sure you drink enough water and/or other replenishing liquids throughout the day.  You should never be embarrassed by leg cramps no matter what your age (unless there's some overriding problem).  BUT, it's happened to me, infrequently, and one of the above two causes is always the culprit.  No reason to be caught unprepared.

I've been meaning to post on this very topic for the last week, but never got around to it.  I am glad I am not alone in this one.

I was going to title it "Coitus Interruptus of the Lamest Type."

This usually happens when the matress is too soft, I've been "pounding" more rapidly and energetically than is my usual practice, or a few minutes into cowboy.

Is there anything that can be done to avoid this?  Yeah, i know, hold the genius resposes like "avoid overly soft matresses, don't pound energetically beyond your capabilities, and avoid cowboy."  I've already figured those out for myself.

My cramps generally occur in the mid-thighs, which are heavily muscled, and less frequently in the calves.  On a couple of  really painful occassions the ankles and achilles tendons have turned into stone. Hurts like the dickens. I jumped off the bed, don't ask me how,  and fell flat on my very chagrined face. She no doubt had quite the amusing tale to share with her femme cronies.

So, i'm thinking, the usual nostrum is bananas and potassium-rich foods.  To which i've added some salt tablets and additional fluids.  Should I strech before getting down to action? Should i break down and take up yoga? Any sage advice to impart here?

it happened to me also and I also am getting up in years at 59. I thought it was a potasium thing but when I was at my accupunctuist she told me I could not maintain calicum. She gave me treatments for it and I take supplements now and never had a leg cramp since.

Man - I know off if she was laughing but I still am! You create a great visual and been there a few times but never with a lady! Luckily - but who says it can't happen. I took up Yoga and Tai Chi to work those muscles in different ways!

I guess it is time to eat more banannas?

I used to get cramps in my calves during sex, when I was in my thirties and forties. Some of them really hurt like hell; all that I could do was to massage the area and wait it out.

Since then, I quit drinking and started eating more fruits, mainly bananas, and I have not had the problem for a long time.

I think that the posts about potassium and dehydration are both correct in my case.