Jarron Collins jokes he missed 'red flags' that his brother, fellow NBA center Jason was gay

Jason Collins would always make excuses for why he wasn't interested in the girls his twin brother and sister-in-law would set him up with on dates.

Jarron Collins still never figured out that Jason was gay.

Jarron jokes Wednesday on ABC's "Jimmy Kimmel Live" that he missed "red flags" about Jason, who recently came out as the first gay male athlete in one of the major U.S. sports.

The brothers, who played together at Stanford before playing in the NBA, appeared together on the show and discussed how Jason finally let Jarron know after being hesitant for so long.

Jarron was supportive but says he didn't know how to respond at first, saying things such as "Are you sure?" and "Since when?"