The stars shot to international fame after writing and starring in hit 1997 movie Good Will Hunting, which won the pair a Best Screenplay Oscar.
The pair had been friends since they were young, and their closeness sparked gay rumours at the height of their fame.
Damon and Affleck ignored the gossip, and now the Ocean's Eleven star reveals he feared he would offend his homosexual pals if he spoke out about the speculation.
The married father of four says, ""I never denied those rumours because I didn't want to offend my friends who were gay - as if being gay were some kind of disease.
""It put me in a weird position in that sense. The whole thing was just gross. We both have a lot of gay friends and we were not going to s**ew this up or bulls**t it.""