From the BuzzFeed article, around 1990 Rapp talked about his encounter with Spacey with a former boyfriend :
"As Spacey's career blossomed, Rapp could no longer pretend like he didn't exist. He cannot recall precisely the first person he told about his experience, but he knows he started around the time he costarred in the 1990–92 Broadway production of Six Degrees of Separation, the same season Spacey gave his Tony-winning performance in Lost in Yonkers. (One of Rapp's former boyfriends confirmed to BuzzFeed News that the actor shared his experience with Spacey around 1990, when they were both 18. Another friend, actor Erin Quill, confirmed Rapp first told her about Spacey around 1992. And five other friends of Rapp’s have confirmed that they’ve heard the story from him through the 1990s and 2000s as well. Rapp and I have been friends since 1999, but he only shared the allegations with me in recent weeks.)
The full weight of what Spacey’s success would mean for Rapp finally hit him while he was shooting the 1993 feature film version of Six Degrees. One day at lunch, Rapp looked over to see Spacey sitting just a few tables away, visiting someone he knew. Once again, Rapp froze. Once again, he said his mind raced with the question, “What am I supposed to fucking do here?”"