Jason Collins, the NBA free agent who came out gay on Monday, explained that his younger twin brother didn't know his sexual orientation because he's “really good at playing it straight.”

Collins' coming out has been applauded by President Barack Obama, First Lady Michelle Obama and former President Bill Clinton.

(Related: NBA's Jason Collins: First openly gay professional athlete.)

During on appearance Tuesday on Good Morning America, Collins said that the first family member he came out to was his aunt, who said she already knew.

“I have a special relationship with my aunt. I love my parents and my brother and everyone else in my family. But there's just something about the way that I get along and just relate [with her],” Collins said.

“She had her suspicions about me, but she was extremely supportive. Yeah, she's a judge in San Francisco, so I guess she's good at reading people.”

When interviewer George Stephanopoulos asked how was it possible that twin brother Jarron Collins didn't know his older brother by 8 minutes was gay, Collins half-jokingly answered: “I'm really good at playing it straight.” (The video is embedded on this page. Visit our video library for more videos.)