So, an old married couple goes to the doc . . .

for their annual checkups. He sees the husband first, and he seems healthy, so the doc asks if he has any complaints. "Well, doc, we're having a little trouble having sex. When we do it the first time, I get all hot and sweaty, but the second time, I get chills, and I feel like I'm freezing."

The doc says he'll ask the wife about it, and then see if he can pinpoint the cause.

So, it's the wife's turn, and she seems healthy as well, and she has no complaints. So the doc tells her about the husband's problem, to see if she can add any insight.

"It's pretty simple doc. It's because the first time is in July, and the second time is in December!"