NBA free agent Jason Collins, former Congressman Barney Frank and Congressman Joe Kennedy III were among the thousands who joined the Boston Gay Pride parade on Saturday.

Collins is the basketball star who came out in a Sports Illustrated cover story in April.

Collins, wearing a Nike #BETRUE t-shirt, and Kennedy marched in the parade and posed for pictures with Frank, the first openly gay member of Congress and the first to enter a marriage with a member of the same sex.

(Related: Nike #BETRUE sneaker celebrates Gay Pride.)

“It's an opportunity to celebrate with my community and celebrate acceptance and tolerance with good friends,” Collins said.

Kennedy, who roomed with Collins while attending Stanford University, added: “Great day. Great day to share with a very good friend. And honored to have him here with us today. The reaction has been incredible. Really proud of him. And proud to be here.”

Kennedy first marched in the parade last year.