"But you can't come dressed like that!" she told him.
In some ways, this was like telling Superman to show up at an affair and ditch the cape and tights for a nice three-piece suit.
But Captain D went with the flow and showed up for the ceremony in a shirt and tie before changing into his alter-ego costume for the party afterward.
It was the Ravens' Super Bowl season of 2000 that dramatically ratcheted up Captain D's profile as a super-fan. Now the Ravens, behind fearsome NFL Defensive Most Valuable Player Ray Lewis, were no longer the league's weak sisters when it came to stopping the other team's attack.
"DEE-FENSE! was the rallying cry on every Ravens fan's lips. That season, the defense set a 16-game record for fewest points (165) and rushing yards (970) allowed. And the Ravens went on destroy the New York Giants, 34-7, in Super Bowl XXXV.
No, no one in the stands was telling Captain D to shut up about the defense anymore.
In fact, just the opposite occurred.
"All of a sudden, I was some kind of defensive [football] genius," he chuckles. "Down at the Inner Harbor, I was getting interviewed on Channel 11 and Channel 5. They were asking: 'Captain D, what do you think about this defense and that one?' So that was kind of funny."
Twelve years later, Captain D is bigger than ever with Ravens fans. He has almost 7,000 Facebook fans, and his smiling face appeared all over the city on billboards for M&T Bank a few years back.
He sits in section 513, row 17 at home games. But unlike Wild Bill Hagy and Big Wheel Burrier, Captain D doesn't feel the need to windmill his arms and scream himself hoarse and breathe life into the fans.
"I never really saw him as a 'crazed super-fan,' " says Patricia Hurst of Abingdon, who has worked a number of charity events with Captain D and has seen him at the stadium. "I've never witnessed him doing anything [outrageous])."
Instead, Captain D sees himself as more of a laid-back, goodwill ambassador for Ravens Nation.
Early in the game, he'll rise from his seat and begin a slow pilgrimage throughout the stadium, stopping to sign autographs and pose for pictures and chat with fans. Rarely does he have a moment to himself.
"Sometimes it's tough to talk to him," says Grossman, who also sits in section 513. "He's constantly having people come up to him. I can't take it. I get about two minutes of conversation. And then it's like: 'I gotta go, Captain D.'"
But these wanderings are no mere ego stroll for Captain D. Making fans smile seems to bring him more joy than anything else. So does reinforcing their sense of community on crisp autumn afternoons.
"That's the best thing about being Captain D," he says.
It's a way of giving back, he says. But he gives back in lots of other ways, too.
Captain Dee-Fense lives in Waldorf with his wife, whom he declines to name, saying she's a "very private person." They have two grown daughters and a granddaughter.
He says he's missed only one Ravens home game since 1996, when he was deathly ill, and one away game, when he took one daughter to college years ago and couldn't find the game on TV in Cleveland, of all places.