The musician wowed the judges at the weekend with his performance, which including playing and DJing at the same time.
MckNasty - real name Joshua McKenzie - told the panel he was hoping to come out of the shadows of his famous brother, rapper Labrinth, who is signed to Simon Cowell's music label.
He said: “I’m always at the back and I want to be at the front.
"My brother is Labrinth, he is pretty cool. I like the fact that I have to chase him.”
And MckNasty didn't tell Labrinth about his audition, revealing: “Did he know I was going to do Britain's Got Talent? No he didn't, because I just felt like i needed to go on the journey by myself and see what happened.”
In fact, he didn't tell anyone, including his mum!
After MckNasty's audition, Simon told him: “I think you’re brother’s going to be really proud of you, I really do."
Needless to say they were all eager to watch his performance back at the weekend, with the 27-year-old revealing to us that he enjoyed a party with the family and friends until 5 in the morning.
Watch our full chat with MckNasty below...