Henry Winkler's wife says the actor tends to exaggerate about the size of his ... fish

Henry Winkler has been married to his wife, Stacey, for nearly five decades, so at this point, she knows him pretty well.

Including, apparently, when he's exaggerating about the size of his... fish.

The "Happy Days" star and his wife joined Graham Bensinger for an interview recently, where the couple talked about their marriage, how they met and the one activity that somehow transforms Winkler from one of the nicest guys in Hollywood into a fiercely competitive rule-breaker.

Fly-fishing.