Oliver Hudson is getting candid about the early days of his relationship with Erinn Bartlett, his wife of 18 years.

On the April 8 episode of his “Sibling Rivalry” podcast, the “Nashville” star revealed that he’d been repeatedly “unfaithful” to Bartlett before the couple was married.

“When I got engaged, something happened psychologically, and I spiraled,” he explained in conversation with fellow actor Robyn Lively, who is Blake Lively’s older sister. “I spiraled, and I was unfaithful, and I was cheating, and I was crazy.”

He went on to note that he “never got caught,” but instead acknowledged his behavior in conversation with Bartlett before the pair tied the knot.

“I told her everything because I couldn’t live with myself and get married and be married and have children with this sort of weight,” he said. “I was crying, like ‘Oh, my God, who am I?’”

Describing Bartlett as an “amazing woman,” Hudson also credited his mother, Goldie Hawn, with offering her support amid challenges in his relationship.

“My mother played a big part in it as well,” he said. “Where, it’s about looking at the entirety and the totality of the relationship, not just the action.”

Bartlett, whose Hollywood credits include “Felicity” and “How I Met Your Mother,” tied the knot with Hudson in Cabo, Mexico, in 2006. The couple share three children: sons Wilder and Bodhi, 16 and 14, respectively, and daughter Rio, 10.

Though Hudson said he regrets “causing pain,” he ultimately has no misgivings about the trajectory of his marriage.

“Honestly, if that didn’t happen, I don’t know what kind of a person I would be,” he said. “Although some choices might be bad, if you can sort of come out the other end of them, and learn from why they were bad and how that affected you and everyone else around you, then you’re only growing and you’re building your toolbox.”

Listen to the April 8 episode of “Sibling Rivalry” below. Hudson’s comments on his marriage begin around the 31:20 mark.