In two studies, lesbians, gay men and bisexuals were queried concerning mistakes that well-meaning heterosexual people have made when interacting with them. In qualitative, open-ended research, we determined that the most common mistakes concerned heterosexuals' pointing out that they know someone who is gay, emphasizing their lack of prejudice, and relying on stereotypes about gays. Following up with a quantitative, close-ended questionnaire, we determined that the mistakes respondents experienced most often involved heterosexuals (a) relying on stereotypes and (b) ignoring gay issues; the most annoying mistakes were heterosexuals (a) using subtle prejudicial language and (b) not owning up to their discomfort with gay issues. We used two theoretical perspectives, shared reality theory and the contact hypothesis, to analyze the quantitative responses. Implications for intergroup relationships between heterosexual people and gay people are discussed.