But before they hit the big time, the couple called a far more modest apartment their home.
Mark recently took a walk down memory lane and gave fans a tour - which you can watch below - of the pad they shared in the Big Apple.
Mark marveled at how, over the years, the owners had overhauled the two-bedroom property, adding in walls, a new kitchen and a brand new bathroom too.
He fondly recalled the bedroom which would become a nursery for their son, Michael, 26, who was welcomed while they were living there.
The Riverdale actor gushed about the view and showed off the expansive patio which still had the satellite he'd installed himself.
While the apartment is far from humble, and likely came with a hefty price tag, it pales in comparison to the New York home they now live in.
Their primary residence is their $27 million townhouse on the Upper East Side of Manhattan. It's ideally located so Kelly and Mark can walk home from work on occasion.
The 7,796-square-foot property has five bedrooms and six bathrooms and reportedly had a complete renovation just before Mark and Kelly bought it in 2013.
Kelly and Mark have been married for 27 years after meeting on the set of TV soap, All My Children, and they exchanged vows in 1996.
Rather than an opulent wedding, the couple eloped to Las Vegas. "We just had a very normal, very regular wedding," she told her former Live! co-host Ryan Seacrest.
"It really is such an efficient way to get married. And it was fun. We were like, 'Now, this is gambling! Woohoo!'"
They jetted from New York to Sin City because they wanted to tie the knot somewhere warm.
"It was '96 guys, remember the winter of '96? The winter of '96 is in the record books as the most miserable," she told the audience. "It was an endless winter, and it was a snowstorm when we left."
Remarkably they managed to get married for under $200. "$179 for a wedding, including airfare," she said. "Because we had miles and we had a canceled trip or something. But $179 in total."
However, she did have to splash out a little more for her wedding dress. "I just bought it because it was really pretty," Kelly said about the outfit, which she wore again to celebrate her 20th wedding anniversary, confessing it is now a beach coverup.
"I wanted to buy something from the Barney's warehouse sale."
I was working on the soap All My Children and I didn't make a lot of money. It was $199 on final clearance sale, and I was like, 'Do I eat this week or do I get this dress?'"
Kelly and Mark went on to have three children, Joaquin, 20, Lola, 22, and Michael.
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