The singer opens up about the ups and downs of having 5-month-old twins
David Nail Twins Patience

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If having 5-month-old twins has taught David Nail anything, it’s that you need patience — “a ridiculous amount of it,” he tells PEOPLE.

“I knew that I was going to have to be patient, but it’s something that I’ve never really been,” admits the father of son Lawson Brent and daughter Lillian Catherine.

“I felt like that throughout my wife’s pregnancy I was subconsciously getting more patient. Things would happen and my reaction would kind of surprise myself. But there’s just nothing that can prepare you for how patient you have to be — especially with twins.”

He adds, “I definitely have a tendency to get a little anxious when they are upset. Obviously they don’t know how to communicate to you what’s the matter. It’s like trying to read a baby’s mind. That’s when I really lean on my wife.”

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Having kids might have helped him to become more patient, but the 37-year-old singer says being a dad has also helped him feel a little older and a little more out of shape.

“I definitely have gained some weight since my kids were born,” Nail says. “You may get an hour out of the day for free time to collect your thoughts or go for a drive and clear your head — the last thing you want to do when you only have an hour is to go to the gym.

“I went golfing with my band last week and I bent down to pick up a ball and almost fell over right on top of my head,” he adds.

Nail is playing in the annual Nashville City of Hope Celebrity Softball Game on Tuesday and says it’s a chance to try to feel like a kid again.

“I played a lot of sports growing up so this is an opportunity I get to turn back the clock and pretend like I’m 18 again, run around and just hope like hell that I don’t injure myself and end up carted off the field,” he jokes.

Regardless of his on-field performance, though, his little ones are already his biggest fans — as well as fans of each other. “A few times a day, we always try to make sure they’re face-to-face and acknowledging each other,” he says.

“My daughter has an amazingly funny personality, she loves to laugh and smile. She looks at her brother and she’ll just start dying laughing out loud.”

— Danielle Anderson