Gentleman's Crush

When an older guy lusts after some person considerably younger and immature, realizing he won't/can't proceed with intimacy/sex because she's just too out of touch with the values and tastes He enjoys.

Hey, Man. You think Pops is gonna hook up with that chick that's swooning and drooling like he's a Tater Tot???

"No, Dude. He told me he's got a Gentleman's Crush on her, and put her off limits. Now they're just friends, but She may not get it..."

Gentleman's Crush

When an older man is infatuated with a younger, more attractive woman who (for a variety of age-related reasons) will Never consummate the relationship, but, when together, treats her as if she were a girlfriend.

"Look, there's Dieter and Jane!"

"They look pretty cozy in that corner..."
"Oh, they Are, alright. But, he's just got a Gentleman's Crush on her, so it can't be that deep..."