Two years ago, my sister, 38, left her college sweetheart and husband of ten years to be with her boyfriend, 23.

She met him in the online gaming world. Their gaming characters have been together for five years – at 33 and 19 - according to their characters’ Facebook pages.

This means she was unfaithful in her marriage. My sister travels a lot for work and it's apparent she was visiting her boyfriend during these times.

She’s college educated and has a great career.

Her boyfriend allegedly got an honourable discharge from the armed forces when he messed his knee up in basic training.

He started community college but quit due to lack of funds. He had a job and lost both it and the apartment he was renting.

His mom allowed him to come back home temporarily. He says he was homeless.

It was then that my sister moved across the country, rented an apartment, and he moved in.

Six months later, she got pregnant. They moved again, for my sister’s work. He got a job as overnight security.

The baby arrived and he became a stay-at-home dad, working just nights/weekends.

They’re now back in the east and he isn't working, but supposed to go to school (on my sister’s dime, I’m sure).

My brother and I met him last weekend. This guy is bad news in so many ways. He swears around my nine-month-old niece. He was showing her how to do the Hitler sign.

He’s a man filled with hate.

My sister had to ask his permission to take the baby on the grass on a blanket. I feel as though the baby doesn't stand a chance with a role model like him.

What’s going on with my sister? And, short of kidnapping her, how can we prevent the marriage that's planned for next year?

My folks are in their 70's and absolutely sick over this.

Desperately Worried Sister

No one can know for sure what will change your sister’s mind about her boyfriend, but one thing is sure: While your negative judgment of him seems understandable to me, it’ll easily push her closer to him. And may even lead to your being excluded from your sister and her daughter’s life.

So move slowly, and think things through carefully.

Her marriage to her college sweetheart and her successful career at work may’ve represented, for her, a feeling that she traded her youth and excitement for others’ expectations of her.

She got emotionally caught up with someone who was the total opposite and brought spontaneity and reckless abandon into her life.

The main link between those two worlds is now her daughter. And that may be the only “hook” on which you can approach her.

Instead of predicting a dire future for the child, have some conversations designed to get her to think, rather than to defend him to you.

Examples: Comment on the fact that her boyfriend has immersed himself in fatherhood… that she must enjoy sharing the baby’s care and handling with him. Don’t be mocking, just let her sit with those thoughts in her own mind.

Don’t make the wedding your deadline for ending her relationship. Stay connected, show your support, and especially your family’s value in the child’s life.

She may still marry him. But if and when she has doubts or discomfort over her decision, she’ll know you’re there to turn to when she needs you. And she likely will.

My best friend and her husband are expecting their first baby.

Meanwhile, she berates him non-stop.

Recently, he picked too many things from their garden. He drinks too much (one last hurrah pre-baby). He says stupid things.

Visiting them is made very difficult by her endless scoffing and criticisms.

This is their dynamic. He's the dopey, whipped husband, she's the know-it-all nag wife.

But now it seems out of control. With their baby coming, I worry it's going to get worse.

Should I say something to her?

Hard to Bear

She may be more stressed now and resent criticism.

Tell her you’re worried about her, that she’s likely anxious about the birth, but they both need gentler time together and mutual encouragement to adjust to this new event.

Say something positive about him and how he needs to be appreciated as much as she does.

Then drop it.

If she doesn’t change, you’ll eventually be recommending counselling.