During an appearance on The Artist and The Athlete with Lindsay Czarniak, Butler revealed Lowry is the godfather of his daughter.
"He's one of my absolute best friends. He's the godfather of my daughter," Butler said at the 30-minute mark. "As competitive as it is, we're always laughing, we're always joking around."
The five-time All-Star added he didn't want to go much further, lest he run afoul of the NBA's tampering rules.
Ahead of the 2021 trade deadline, The Ringer's Kevin O'Connor reported Lowry had Miami as his preferred destination due to his friendship with Butler if the Raptors moved him. While the 35-year-old remained in Toronto, he's a free agent this summer, which frees him up to sign with the Heat.
It looks like Butler would certainly be on board with the idea.