He's a friend of a friend of the owners, a bit simple, he's dropping the owner's vehicle off after servicing, popped in for a cappuccino, sympathizing with the owner over his women troubles. He begins his own narrative:
Something like this. He got married. Suspected his wife was cheating. Hired a private detective. Proved his wife was cheating. Divorced with minimal alimony. He feels pretty smart.
He's a fucking idiot. Only an idiot would tell this tale, he tells it with no shame, he's exactly the sort of man any woman stupid enough to marry would cheat upon. It would be an easy choice: Kill yourself, or cheat on him. WYSIWYG. He's telling us this to make himself seem clever, hiring the private eye and all, but he's an idiot, and the owner sighs patiently waiting for him to finish his ordeal so he can begin his own...but the mechanic won't stop, won't spare us any detail, no matter how salacious, trivial or humiliating, he's proud to wear the horns, he's wearing the horns before he opens his mouth to make the proposal, the women (woman) having made her plans upon meeting him, he's damning himself twice with the retelling of this story but he doesn't get it, he'll be the cuckold as long as he lives and proud to tell the world, he's a fucking idiot...