Metro

They’re ‘Mad’ly in love

From on-screen co-stars to off-screen couple.

Alexis Bledel and Vincent Kartheiser of “Mad Men” go public with their none-too-secret romance on the red carpet at the Bowery Hotel.

Kartheiser, who plays the ethically challenged ad exec Pete Campbell, connected with former “Gilmore Girl” Bledel, 31, when she appeared in the AMC series’ fifth season as his spacey mistress, Beth Dawes.

They were first reported to be dating four months ago, when they were spotted canoodling on a flight from Los Angeles to JFK.

They removed all doubt with their Wednesday-night appearance at the East Village’s Bowery Hotel for an event celebrating the opening of The Macallan Masters of Photography exhibit.

“I’m a really lucky guy,” Kartheiser, 33, told Us Weekly.