Carolyn Hax: Cheating SIL has sister seeing red

Dear Carolyn:

Last summer, my sister-in-law cheated on my brother. It was a monthslong affair that continued even after my brother found out about it, and was followed by some other odd/out-of-character behavior that led my brother, and eventually her, to suspect mental-health issues.

Although it seemed like they were headed for a divorce, she abruptly agreed to start attending therapy and working through their issues.

They announced they are expecting a baby this summer. The rest of my family, none of whom knows about the affair, is over the moon.

My brother understands where I’m coming from, but it’s still awkward when we talk. Any advice? I want to share in his joy, but I’m horrified that a baby seems to be how they decided to patch up their marriage (as far as I know, they’ve stopped going to counseling).

And I want to forgive my sister-in-law, but my hatred for her is still very real and very fervent.

– Sibling

There is a time and place for skepticism like yours: When you’re the one deciding whether to marry/reconcile/procreate with someone, or you’ve been asked to advise the person who is.

But here the decisions have been made, and your counsel is not being sought. Now it’s time to make your sister-in-law the beneficiary of any doubt.

You know a lot less than you think. You know she cheated, they reconciled, they conceived. Beyond that, zip. So embrace that, make it work for your brother, if not for you.

Start by forgiving her.

Next, re-spin all your “seems like” conclusions in your sister-in-law’s favor:

Affair? Maybe it was the byproduct of poor mental health, which is now being addressed.

Baby as marital glue? Terrible idea, yes – but maybe it wasn’t an idea. Maybe the pregnancy was unintended. Maybe it galvanized them. Maybe they’ll beat the odds.

Counseling? Maybe they still go.

You don’t need any of this to be true, or even likely – you just need possible, enough to invest you in your brother’s success.