"Ashlee's been my best friend for five years; she's the mother of my child. I have nothing but love and respect for her and going through something like this isn't easy, but we're friends and the most important thing is to put our son first," Wentz said.
He's also expressing gratitude for Sheen...
Wentz explained to Seacrest that one of the hardest things he's dealt with during the breakup has been the attention the couple's relationship has gotten in the news.
"I think that one of the things, the hardest thing, is that when you're a public profile it's hard to maintain your private life, and you wanna do it especially when there's a kid involved," Wentz said. "It's like the one time on earth I'm like, 'Thank God, Charlie Sheen exists.'"
Regarding the couple's child, Wentz has filed papers in response to Ashlee's sole physical custody request, requesting both legal and physical joint custody of two-year old Bronx Mowgli. The proud papa shared a bit about his boy.
"Bronx is doing awesome," Wentz said. "It's something new every day. Everything's a new discovery for him. He's opening doors and he wants to paint. He hides cell phones and credit cards."
Besides talking about his personal life, Wentz was on the KIIS FM show to promote a new song called "Summer Nights" from his new band, Black Cards.
"It's UB40 meets No Doubt meets Lily Allen," Wentz explained. "When Fall Out Boy went on hiatus, I was in New York and hanging around and had a crazy beard and was wearing lumberjack shirts. I didn't really feel like doing music right now...I went in and goofed around with ideas and I was into a reggaeton."
Wentz said he went into the studio and began playing around without a singer—but then heard one in the next room whose sound he loved.
"A girl named Bebe Rexha from Staten Island," Wentz said. "We made an album that's strange—it's a body of work, the songs only make sense when it's on a whole album."
But even with the new band, Wentz says his old group isn't completely finished.
"We're like, 'Let's take a break and step away and everybody get out their personal ideas,' " he said of Fall Out Boy. "We're probably tighter as friends now."