The Instagram post showed an old photo of the eighth immortal kissing his former Newcastle teammate Bill Peden, while holding a beer.
The light-hearted photo was captioned: "2 boys from Cessnock will be voting yes . Ha ha sorry bill".
Bill Peden played 190 games for the Newcastle Knights and won two premierships, in 1997 and 2001, with teammate Andrew Johns.
The light-hearted photo comes as Australian sport stars emerge to share their views on the same-sex marriage postal survey.
Ian Roberts, the first star rugby league player to come out as gay, won the commitment of the NRL to publicly support same-sex marriage.
Israel Folau sparked a Twitter backlash by revealing he will not support gay marriage, becoming the first high-profile sportsperson to have publicly announced their opposition.
Sydney, June 25, 2003. NSW's Andrew Johns after winning game 2 of the State of Origin at Telstra Stadium. NSW defeated Queensland leaving game 3. Source: DIG
The majority of Australian sports codes have come out to support same-sex marriage.
