Gavin Rossdale and Kingston
Andrade-Butterworth/Pacific Coast News
Kingston Rossdale is still adjusting to life as a big brother.
"It's like, here is this guy, and he's not leaving. [Kingston] is getting used to that," dad Gavin Rossdale tells PEOPLE about 2-month-old son Zuma
with wife Gwen Stefani. "Obviously, there are moments that he's bugged out that someone is in his spot with his mom."
Rossdale, 40, joked, "His mom is great, so I agree with that. I just can't complain about it. I think it's just natural. That's what happens."
Of having a second child, Rossdale also kidded, "One is one, and two is 10. That's all I know." But seriously. "It's going really well. It's not so bad. We've got it down now, you know."
Rossdale spoke with PEOPLE at a VH-1 Save the Music Foundation benefit at Esquire
magazine's Hollywood Hills House, where he performed a 25-minute acoustic set of songs. Wife Stefani, 39, did not attend.
A Save the Music representative, Rossdale is easing Kingston, 2, into the family musical tradition. "He's got good rhythm. So, I'm happy about that it. I don't push him beyond that. I let him enjoy it," said the rocker. "He listens to lots of music, he really enjoys it. He likes a good beat."
And in other family news, the boys are ready to go with their Halloween costumes: "One's an elephant, and one's a shark," said Rossdale. "Zuma's the shark."
A fan of the Stefani-Rossdales? See more images in their family photo album!