Usher's children wear him out.
The 'OMG' hitmaker admits his sons Usher V, two and 20-month-old Naviyd Ely - his kids with ex-wife Tameka Foster - can be mischievous but he loves watching their naughty antics.
He said: "They play really well with each other. They have their differences, but they're definitely brothers.
"They're fun to watch together and both have a ton of energy. They can wear me out sometimes, without a doubt.
"Usher V is always in everything. He's the one who leads his brother astray - he's the instigator. He'll be like, 'Hey, let's swing from the table,' and his brother will follow him. He's the one who's responsible when they get into trouble."
The 31-year-old singer is delighted there is no sibling rivalry between the boys, with his youngest son "worshipping" his brother.
Talking about Usher V, he told People magazine: "He'll read books to Naviyd. Well, he can't read, but he's memorized the books and will recite them. Naviyd worships the ground Usher walks on.
"If Usher gets something to eat, Naviyd wants the same thing. If Usher wants to watch something on TV, so does Naviyd."
Usher - real full name Usher Raymond IV - also claims having children has made him become a "real man".
He said: "It really hits me that I'm responsible for raising them and showing them what a real man is. I don't know if I always do it right, but I'm trying."