Coolidge Effect is a phenomenon whereby males show continuously high sexual performance given the introduction of new receptive females. This phenomenon is seen in nearly all species that has been put to test.

I have seen the term “Coolidge Effect”  being used by journalists in describing similar situations which they cover in their news beat.

The term comes from an old joke -

The 30th President of the United States Calvin Coolidge and his wife allegedly once visited a poultry farm. During the tour, Mrs. Coolidge inquired of the farmer how his farm managed to produce so many fertile eggs with such a small number of roosters. The farmer proudly explained that his roosters performed their duty dozens of times each day.

“Perhaps you could point that out to Mr. Coolidge,” pointedly replied the First Lady.

The President, overhearing the remark, asked the farmer, “Does each rooster service the same hen each time?”

“No,” replied the farmer, “there are many hens for each rooster.”

“Perhaps you could point that out to Mrs. Coolidge,” replied the President.

Heh.

[Source : Wikipedia.org]