The other night, I was at a gathering of The Girlfriend’s entire fam-damn-ily — her mother turned 60 last week, so we were celebrating her achievement of that particular milestone — when the conversation turned to the subject of twins. The Girlfriend’s sister-in-law is a twin, and as she and The GF’s brother are currently trying to spawn for the second time, everyone was wondering if twins are a possibility.

Anne’s twelve-year-old niece — the daughter of the other sister-in-law — was having a very difficult time wrapping her head around the difference between identical twins and fraternal twins. She seemed to think that twins = identical, and it didn’t matter if there was one egg or five involved in the production process, or if the twins in question are opposite genders or a matched set. If you’re a twin, you’re identical to your other twin.

Sister-in-Law #1 — the one trying to get pregnant — patiently ran through it all again, pointing out that she and her twin brother couldn’t be identical because he was a boy and she was a girl.

The Twelve-Year-Old framed her face in her hands and said, “But your faces are the same, right?”

There are times when I just can’t help myself. I really should try and keep from blurting things out, but, well, I tend to just do it anyway. This was one of those times. I couldn’t just sit there and listen as the explanation cycled back to Line 1 and continued running in an endless loop. So I leapt into the conversation and said, “Try looking a little south of the face and see if you can spot the difference.”

You know in the movies how they interrupt party scenes with that hackneyed needle-scraping-across-a-vinyl-record sound? (Does anyone under the age of 30 even know what that sound is these days?) That’s pretty much what happened here. Silence instantly fell across the living room, almost like someone had dropped a big glass bell jar over my head. A fork clattered against a plate, no doubt dropped from numb fingers. I felt my face flush as I realized I had just uttered — gasp! — an innuendo. In the presence of Anne’s very conservative and religious parents. I felt all the goodwill credits I’d racked up during the Great Disneyland Vacation in October start to ooze down the drain, like soap scum.

Then Sister-in-Law #1 laughed as if that was the funniest thing she’d heard all week. She laughed even harder when I compounded my initial remark by referring to what lies south of the face as a person’s “bits.” As in girl-bits and boy-bits. The laughter spread through the room, and the tension was broken. I’m still in the black in the goodwill ledger.

While I breathed a sigh of relief, The Twelve-Year-Old continued looking confused and ultimately dropped the subject. Meanwhile, The Teenage Niece’s Boyfriend caught my eye and said, “You know, two or three years from something will click in her head and she’ll say, ‘That’s what Jason was talking about!'”

No doubt.