THURSDAY, Oct. 11, is National Coming-Out Day, an annual celebration of living openly for people who are lesbian, gay, bisexual or transgender.

Some people approach this particular square on the calendar with pride and courage, others with trepidation. Then there’s a third group, which gazes at the day with an uncomfortable blend of longing and impatience. These are parents who know, deep down inside, that a son or daughter is almost certainly gay, but hasn’t worked up the nerve to open up about it. And many of them want to scream, “Would you just come out, already?”

Parents aren’t blind, and the clues are often there. Some research suggests that sexual orientation can show itself even at 3 years old. In our family, by the time our youngest son came out at 13, my wife and I had long progressed from inkling to conviction. A toddler who wore a feather boa around the house and pleaded for pink light-up sneakers with rhinestones is probably telling you something, even if he doesn’t yet know what it is.

We’re not the only ones, said Ellen Kahn, the director of the Family Project for the Human Rights Campaign, a leading advocacy group for gay men and lesbians. Recalling that her own tomboy ways served as a signal, she said, “I was one of those kids, and my parents were those parents.”