"Welcome to 'Lopez Tonight,' where nobody gets fired, they just get replaced by a bigger star with the same last name," Jennifer said to a surprised audience during the show's monologue, which is usually delivered by host George Lopez.
And the barbs from J.Lo were just getting started.
"Last week was the first anniversary of Sully Sullenberger landing his plane safely in the Hudson. A bar in New York has named a cocktail after him. The drink is a Manhattan - with a splash… It's such a big hit, now the same bartender is making a drink for Conan it's called The Go-Back-To-Manhattan… It's a Manhattan with sour grapes and a knife in it," she joked.
However, Conan wasn't the only late night host to come under fire from the singer/actress.
"NBC is thinking about changing the NBC peacock to a cougar, since they are trying to attract young people to an old host," she joked. "Some women don't like the expression 'Cougar' but it's better than what guys get, right? An older guy who dates a younger girl that's called a 'Letterman'."
When he finally reclaimed hosting duties, George called Jennifer's monologue "amazing."
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