Metro

Kelsey’s secret $6.5 mil love nest

The wife is always the last to know.

Kelsey Grammer’s spouse, Camille, was blindsided when he launched a torrid affair with a much younger woman. And now she’s about to learn her soon-to-be ex has plunked down $6.5 million for a love nest he’ll share with the hot 28-year-old flight attendant.

They’ll soon be shacking up at 100 Eleventh Ave., the sexy glass building on the Hudson designed by starchitect Jean Nouvel.

Several sources told The Post that the former “Frasier” star, who’s in the midst of divorce proceedings, was “adamant” that the deal be kept deep under wraps. Everyone involved had to sign top-secret confidentiality agreements to keep his wife from finding out.

The 55-year-old Grammer, who was previously renting at the star-studded 15 Central Park West, and his latest squeeze, needed the extra space.

The four-bedroom apartment is big enough for his two young kids when they visit from LA, where they’re living with their mom, a “Real Housewife of Beverly Hills.”

Camille Donatacci Grammer has said she feels “very bitter,” not to mention “humiliated,” about Kelsey’s decision to dump her because of his liaison with Kayte Walsh.

Camille is Kelsey’s third wife and the mother of two of his four children.