Rob Lowe shares the secret to his long marriage: 'You gotta keep the heat!'

Rob Lowe has revealed the secrets behind his three-decade marriage to Sheryl Berkoff.

Former Brat Pack star Rob, one of the biggest pinups of the '80s, tied the knot with make-up artist Sheryl in 1991, with the couple going on to welcome sons Matthew, 30, and 28-year-old John.

Talking to iHeartRadio's Table for Two with Bruce Bozzi podcast, Rob was in a reflective mood when it came to his successful partnership.

Calling Sheryl his best friend, the 59-year-old insisted marriage was hard anywhere, not just in Hollywood, and listed forgiveness and keeping the spark alive as the secrets to longevity.

"People say marriage takes work. I'm not sure if it takes work, but what it does take is forgiveness, and being really cognizant of what hill you're willing to die on," Rob mused.

The West Wing star added: "I do believe you need the heat for sure. If you don't have the heat – and that's a chemical thing – I mean I still have it with Sheryl, you gotta keep the heat. That comes and goes too, there are times when you are like, 'Nah.' And then there are times when you are wild for somebody."