Dear Carolyn: I have a friend who I worry is drifting toward an affair. She’s very flirty with a co-worker and talks about him in a crush-y way, while she and her husband seem to be going through a rough patch. The rough patch seems symptomatic of external stresses in their lives, not fundamental incompatibility.

I’ve tried to be there for her, both to talk and to go out and have fun. Is that enough? I am not married, so I feel underqualified to speak up. Plus, no one can know what it’s like inside someone else’s marriage and/or head, right? I can see how a lighthearted, quasi-platonic workplace flirtation could be an excellent escape from what seems like a very grown-up, dreary life.

There’s no upside to raising the subject (she’d either be rightfully offended if I’m wrong, or defensive if I’m right), but it’s hard to watch someone you love edge closer to a baaaaad decision. – Maryland

It’s also hard to watch someone presume bad behavior, as if there’s no real alternative.

I don’t mean her flirtation, but your casual presumption that of course she’d be offended or defensive if you raised the subject.

You’ve clearly given this a lot of good thought. Please keep going, though, and consider that she might appreciate knowing how things appear, even if you’re wrong, if only so she can check herself to keep her husband from getting the same mistaken impression. If you’re right, then she might be grateful you snapped her out of denial.

This isn’t to argue that you must speak up. There’s also an excellent reason not to: because she’s an adult and this is her baaaaad decision to make.

Your adulthood door prize is that choosing among these options falls to your conscience alone.

Speaking of adulthood – “a very grown-up, dreary life”? Is that your take, or hers? And your “no upside” view of speaking up – is that based on your history of taking offense, or hers? The pretext of your letter is to navigate the line between helping and meddling, but if you squint you can make out another line running through your question, between childhood and adulthood. Hers, yours, maybe both?

Just as stressful times don’t always make for a dreary life, and crushes don’t always become bad decisions, and raising a delicate issue isn’t always apocalyptic, friendship doesn’t always mean doing something. People, loves, lives are both elastic and complex. Sometimes the most helpful friend is simply the one who gets it.