"It's still unreal," McMahon said.
The 6-foot-1, 175-pound McMahon is a sharpshooter from Sarasota, Fla., Cardinal Mooney and gave the Cardinals' a commitment after a brief recruiting period by Pitino and his staff.
"It really did all happen so fast," McMahon said. "Coach Pitino sent (assistant Mike Balado) to see me and then he came and watched a game. They came back and then he called and said he wanted to offer me a scholarship, it's just all still so surreal."
But it sank in a little more this weekend when McMahon made his second visit to the KFC Yum Center and watched the Cardinals take down No. 2 Virginia on Saturday.
McMahon had made his official visit on Jan. 31 with his father, Dave, but came back this time on an unofficial visit and was with his mom and dad.
"My mom wanted to learn more about the academics," he said. "She did that and she's really happy. She liked it a whole lot."
McMahon was sitting five rows behind the bench when Mangok Mathiang hit the game-winning 17-foot jump shot with 2.7 seconds left for U of L.
"He didn't hesitate and stepped up when they needed him," McMahon said. "It was a big-time shot and was awesome to see."
While he saw the crowd earlier in the year against North Carolina, McMahon said this atmosphere was "really incredible."
I'm so excited for next year," he said. "It felt like the Cougar Crazies (at Cardinal Mooney) multiplied and they all traveled to the Yum Center.
It was really cool to see. The visit was great! I got to know the players a lot more and hang out with them a little more than I did on my first visit so that was cool."
McMahon, who will sign next month with the Cardinals, averaged 28.5 points a game and helped Cardinal Mooney to the Class 3-A state semifinals.
He will play in the Derby Festival Classic next month.