In these narratives, the dog absolves the man of the sin of vulnerability. He didn't choose to approach a woman; his dog forced him. This removes the stigma of desperation and replaces it with the virtue of responsibility.
This trope is effective because it bypasses dialogue for instinct. We trust dogs because they lack social artifice. In the 2021 rom-com The Lost City , Sandra Bullock’s character is initially repelled by Channing Tatum’s vain cover model persona. But when she witnesses the gentle, unguarded way he interacts with a wild capuchin monkey (close enough to a dog in narrative function), her infatuation begins. The man-dog (or man-monkey) relationship signals a hidden depth that luxury goods cannot. man dog sex best