I’m a gay guy in my late 40s with a straight sister in her early 50s. My sister has been married for a bit more than two decades to a guy who always registered as a “possible” on my average-to-good gaydar. But I put “BIL,” aka my brother-in-law, in the “improbable” bucket because he actively wooed my sister, was clearly in love with her, and fathered four boys with her, all in their late teens now. I’m sure you already saw this plot development coming: It turns out that BIL has been far more “probable” than I thought. He has a boyfriend, but he is still very much closeted and denies he is gay. My sister has apparently known about this arrangement for four years, but has kept it a secret for the kids’ sake. But she recently filed for divorce and told our parents and me what’s been going on. Their kids have been informed about the divorce,...