I honestly didn't even know about all the lesbian jokes related to them until I saw one in an older episode of Family Guy. IIRC Peter was looking up some old girlfriends of his for reasons I can't remember and Peppermint Patty was one of them. When he went to her house he was like "wow time's been nice to you" (because another joke is most of the old girlfriends Peter had haven't aged very gracefully, one is still utterly obsessed with him to the point of insanity while another became total white trash) and then Marcy comes from around the corner and says "who is it sir?" to Patty and they give each other a quick kiss, the joke obviously being two fold since it plays into the "lesbian" rumors/jokes and shows "the only one of Peter's old flames that's actually stable is someone who wouldn't be interested in him sexually anyway."