Lyric discussion by Musicpsych0 

Cover art for Pink Triangle lyrics by Weezer

This song is about a gorlfriend that rivers had that turned out to be a lesbo! haha pretty cool

@Musicpsych0 Wiki's source seems to suggest she wasn't actually a lesbian (and the man may not necessarily have been him): "The song is based on a real person that Weezer frontman Rivers Cuomo encountered while a student at Harvard. Years later, he discovered that the woman was actually not a lesbian but merely showing support for the gay community by wearing a pink triangle"