You can’t, and please don’t.
You’re not in this spot because you implied Grandma’s boyfriend is a child molester. You’re in this spot because Grandma wouldn’t take no for an answer. She applied enough pressure to force you either to make up flimsy excuses or admit something you’d rather have left unsaid.
Your reservations about Grandma’s boyfriend are so devastating that there was bound to be some strain whether your mother-in-law pushed or not. But even if your discomfort was entirely unfounded, refusing the overnights was your only choice.
And as someone who loves your daughter, Grandma would likely agree. Let’s say we could go back to before things unraveled, allowing you to pose this scenario to her in conversation as a hypothetical — say, in response to a news story. She’d likely be unequivocal in agreeing that these hypothetical parents should never leave a child in a situation they felt uneasy about.
Not to mention: Parents get to say no, period, even for their own stupid reasons.
Trust this, please. Trust that your mother-in-law put her feelings and ego and need(iness) above your fundamental entitlement to decide what’s best for your kid. Her error has cost you dearly, too, I get that, but better that than the much higher possible price of overruling your gut.
I think when someone’s that far over the line, the line can file a missing-person report — but that’s based on your version of events, my values and zero context, so it’s of little practical use.
Fortunately, you don’t even have to make that call. Where we don’t trust our sensitivities, we’re often solid on our likes and dislikes. “Not liking her much anymore” is game over because a friendship without fondness is a lake without water.
This one does cry out for irony punctuation, doesn’t it? This “friend”ship.
Anyway, if you still want to parse the boundaries, then I suggest a basic formula: Take the current situation, compare it with prior circumstances, see what has changed, then ask yourself whether and why those changes matter. That’s a one-size-fits-all shortcut for when you’re not sure what you’re feeling or whether you’re justified.
For example: My friend is saying suggestive things about my husband … and she has never gotten jokey-possessive of my love interests before … and this suggests there’s a genuine attraction behind her comments … which tells me she’s thinking more of herself than of my feelings or our friendship when she chooses to say them out loud.
I also suggest you at least consider ongoing support to help you navigate boundaries, be it through programs for adult children of alcoholics or Al-Anon or private counseling. Even with shortcuts, it can get complicated.
Speaking of shortcuts, here’s another: When you tell someone you’re uncomfortable with something, a real friend is willing to consider and apologize for his or her part in that, and to talk about how to fix it. Note, that doesn’t mean real friends automatically defer to you — just that they’re willing to question their own actions simply because someone they love is upset.
Instead, your friend dismissed your discomfort out of hand. Please don’t let that get lost in the clutter of doubts.