My girlfriend’s sister has become the third person in our relationship

DEAR DEIDRE: SINCE my ex and I got back together, her sister has become the third person in our relationship. 

Whether she’s overstaying her welcome at our house, involving herself in our business, or being possessive over my wife, she’s driving me mad.

I’m 35, my wife is 32, and we’ve been married for five years. Her sister is 29.

They’ve always had a close relationship, but since we decided to rekindle things after separating for three months, they’ve become entirely codependent.

Every week, without fail, she’ll spend at least three to four days over our house, and every time she sleeps over, she and my wife stay in the same bed.

At first, I tried to be understanding. I knew my wife had heavily leaned on her when we separated, so I knew it would be an adjustment. 

Yet, now it’s been four months, and there’s no sign of anything changing. 

To make matters worse, she has a tendency to overstep when it comes to our relationship. She’s constantly making comments about me and what I could be doing differently, and if there’s any conflict between my wife and I, she’s the first to offer unsolicited advice.

I’ve tried to explain to my wife how this makes me feel, but she always shrugs me off and says I’m overreacting. 

I’m trying to repair our relationship but this is really getting me down.

DEIDRE SAYS: You’ve tried to be understanding and tolerant in this situation, but it’s clear that your sister-in-law is causing issues between you that need to be addressed. 

You need to talk to your wife – alone – and explain exactly how you feel. Tell her that while you’re happy for her sister to spend time over your house, you need your own space and time together.

It would be best to set boundaries together. Perhaps you can decide on one day a week for her sister to stay instead. 

My support pack, Standing Up For Yourself will help you be assertive.