Liam says he no longer discusses his personal life in order to avoid "complicating things."
"I just find it's easier to not talk about my personal life because usually I say the wrong thing, so it ends up just complicating things more," he admits. "So, I feel like it's better not to talk about it."
Still, there's no hiding that Liam and Miley have rekindled their relationship. The two were snapped holding hands on Sunday as they made their way through Los Angeles International Airport, after spending some time together in Brisbane, Australia. The 23-year-old singer also appears to be close to the Hemsworth family. Last month, she was spotted enjoying a lunch date at vegan restaurant Gracias Madre in L.A. with her beau and his older brothers, Chris and Luke, and Luke's wife, Samantha. She also recently got a matching wave tattoo with Liam's sister-in-law, actress Elsa Pataky, who's married to Chris.
Liam tells ET that the tight-knit family is definitely planning "something special" for their mom, Leonie Hemsworth, on Mother's Day.
"My mom's actually in America right now, so we'll do something special," Liam says, referring to himself and his brothers. "She's really happy for [our success]. My mom and dad are both retired now, so they're able to kind of travel with us and hang out and be in our lives more and more, which is good. For the first few years I was in America, I'd only see my parents once or twice a year, and that was really hard, but we manage to see each other a lot more now."
"It's basically a continuation of the first movie [Independence Day] 20 years later, and we pick up and see where Earth is and how they've rebuilt, and how they've sort of spent the last 20 years preparing for another attack, and the aliens come back," he explains. "It was a little scary, I guess, signing on to another big franchise -- or what could be another big franchise -- but I was really excited to work with Roland Emmerich -- I've been a big fan of him for a long time."
Liam also jumped at the chance to work with veteran actors Jeff Goldblum and Bill Pullman, who reprise their roles in the sequel.
"Just stepping onto set and hanging out with those guys -- Bill Pullman's one of the nicest people, Jeff Goldblum's one of the nicest people, and just, you know, great actors -- a lot of fun to be around," he shares.
Liam's obviously in great shape in the film, and still is, thanks to his latest project. The actor is set to join Land Rover and Ben Ainslie Racing (BAR) as the "6th Man" on the Land Rover BAR boat, to help the British Challenger in their quest to "Bring the Cup Home to Britain" for the first time in over 165 years.
"I sort of had an idea that it was a pretty popular thing to do, but after being on this yacht and sort of witnessing it firsthand, I have so much more respect for these guys and what they do," Liam says about the incredible experience. "It's just amazing the coordination they have, and the communication, and just everything they're doing -- I have no idea what's going on but it's incredible to watch."
"When I'm working, I'm definitely exercising a lot and eating really healthy and being strict about that kind of stuff," he shares. "[But] as soon as I'm not working it's, like, the opposite -- pizza all day long and do nothing and play Xbox."
Though Liam, of course, has his adorable dogs to keep him company! Liam also chatted about the adorable rescue dogs to ET, admitting that the super cute Dora -- whom Miley actually helped him adopt last November from an animal rescue organization in Los Angeles -- is actually named in honor of his niece and nephews.