Ashlee Simpson and Evan Ross Dish on Possibly Expanding Their Family (Exclusive)

The pair already have one child together, and are debating whether to have another kid -- or five!

Two is just not enough for Ashlee Simpson and husband Evan Ross!

Simpson and Ross have talked about expanding their family in the past. But now we have a better idea of how many more kids they want -- and they're definitely of two minds about it.

The couple recently sat down with ET's Keltie Knight  to talk about music, Ross' famous mom, disco/soul goddess Diana Ross, their new clothing line and their growing family. The couple married in 2014 and have a 2-year-old daughter, Jagger, and Simpson is also mom to 9-year-old son Bronx from her previous marriage to Pete Wentz.

But two is definitely not enough, the couple told ET.

In discussing Jagger's upcoming third birthday in July, Ross said, "She changed my life, it's been amazing."

"Definitely more kids in the future," Simpson responded. "Well a kid, another kid."

"I want five more, she said one more," Ross added.

"I'm like, take it one at a time," Simpson said, laughing.

The couple heaped praise on Ross' mother, whom they call "Mama D," who pitched in on the couple's upcoming album of duets.

"She actually came up with a melody that we ended up writing a song to," Ross said.

"That was fun," Simpson agreed.

Best of all, she said, Mama D has been super supportive of their growing family.

"Mama D's like super supportive so I feel like with her she's like you know on our team you know for sure so that's nice," she said.

Aside from building a family, the couple has stayed super busy. They have a new, unisex clothing line that they designed together called Jagger Snow for Zadig & Voltaire, that grew out of a hilariously common couple issue: stealing a partner's clothes. Simpson admitted that she's the bigger thief of the two, but it's definitely not a one-sided thing.

"Yeah, I have like a good like vintage rock t-shirt collection that you like to steal and I have like a lot of amazing kimonos that I feel like you like to," she said.

"Yeah, and she takes all my jackets," he added.

The couple is also working on their new E! reality show, Ashlee and Evan, which will them raising a family and their work collaborating on their upcoming duet album.

For more on their family, watch the video below.