AJ McLean's daughter wants to spend more time with her dad.
ET's Kevin Frazier caught up with the 41-year-old Backstreet Boys member at the premiere for Avengers: End Gameon Monday, and McLean opened up about the stress his career success -- which includes an upcoming solo album, the conclusion of Backstreet Boys' Las Vegas residency, and a world tour with the group later this year -- is causing his kids. McLean shares Ava, 6, and Lyric, 2, with his wife, Rochelle.
"My oldest... asked can I stop being a Backstreet Boy and just be her dad," McLean recalled of a text, which he previously told ET Live about at the ACM Awards earlier this month. "Because my schedule has been really hectic lately between solo, between Vegas, between rehearsals for the DNA World Tour and then going on tour."
McLean called his daughter's request "a virtual dagger" and said he feels its affect "daily."
"That's something that, like, a 16-year-old says. Not a 6-year-old," McLean quipped. "Both my girls are extremely intelligent and they know now that if daddy's leaving to go the mall, he's back in a couple of hours, or if daddy leaves and he's not coming back for a couple of weeks or months."
"So the first leg of our DNA Tour is in Europe. Seven weeks. And they're not able to come out because of school and what not," he continued. "So I haven't told her that yet. I'm waiting."
In addition to his exciting projects, McLean's family was also displaced due to the recent fires in California and haven't had a steady home base for a while.
"We've been displaced by the fires so we've been bouncing from rental to rental. So it's just a lot of stress for a 6-year-old," he explained. "But hopefully we'll be back in our house by the end of May. I'll be on tour sadly so my family has to move in without me."
Even with an incredibly busy upcoming period for the singer, McLean managed to carve out enough time to attend the Avengers: Endgame premiere, after having never missed a single premiere in the franchise.
"Robert Downey [Jr.] has actually become a dear, dear friend of mine. He is one of the sweetest, most talented, most genuine human beings on the planet and he has always been so gracious to hook a brother up," McLean said of getting to attend the event. "Out of all my brothers in the band, I am the most obsessed with Marvel. Obsessed."
Despite McLean's friendship with Downey, he never tried to get any spoilers out of Iron Man himself, insisting that he doesn't "want to know."
"I don't ask. I don't want to know. I sometimes won't even watch the actual trailers. I don't want to know nothing," he said. "Cause sometimes they give too much away in trailers, you know what I mean?"
McLean admitted that he has "a couple of theories" about the film, after hypothesizing over it at length.
"I'm really curious to see. I have a couple of theories of how this is going to pan out, but I'd be shocked if one of them is not close at least," he said. "I think Captain Marvel is going to be the one that actually takes down... or Thor. I really believe one of the two or combined. But we'll see."
"I don't sleep over this," McLean quipped. "I don't sleep."