The couple tied the knot in Santa Ynez, California, in 1999, with Marisol wearing a gorgeous satin Vera Wang gown and Rob rocking a Gucci tux.
In the lead-up to their 17th anniversary, Thomas told ET that the pair tend to be low-key when it comes to such milestones.
"We pat ourselves on the back every anniversary, but at the same time, when we got married the idea was that we were going to be married as long as we're alive, so we don't want to make too big a deal out of it,” he explained at the time. “We were always headed this way, so it's just about continuing that promise."
However, that pat on the back is well-earned given the trials the pair has faced, with Marisol beginning a debilitating battle with Lyme disease four years into their marriage.
But living with the illness remains a grueling, daily challenge, with symptoms including visual disturbance, numbness, seizures and constant pain
“It’s like if one day you woke up and there was an alien living in your house and the first couple of weeks you’d be f**king freaked out, but after a while you’d name it and it would just be there,” Thomas recently told ET about dealing with a spouse who suffers from Lyme. “This sickness has been like this weird alien that’s moved into our life and inhabited my wife. Sometimes she’s just not herself.”
Thomas’ sweet social media post came as he and his band mourned the loss of Petty, who died on Monday night after suffering cardiac arrest.
“There are no words to describe how much this man meant to me, my band and my family. None,” Thomas captioned a photo of the “Free Fallin’” singer on Instagram.
Thomas' bandmates were also distraught, with Kyle Cook “trying not to sob like a toddler in front of strangers,” while boarding a flight after hearing the news, and Paul Doucette noting Petty’s impact on the group’s music.
“I can not begin to express what he has meant to me and mb20,” Doucette tweeted. “He is our biggest collective influence. He was the bar. And always will be.”
I am currently on a flight trying not to sob like a toddler in front of strangers right now. #riptompetty