Horrified woman reveals how her adult daughter 'blew up' their family by sleeping with her own child's BOYFRIEND: 'How could she do something so awful?

A woman has revealed how her family has been ripped apart after her daughter  slept with her granddaughter's boyfriend. 

The exasperated matriarch, from the US, used the signature 'Just Want a Peaceful Retirement' as she asked for advice from Slate's Care and Feeding parental column.

She assigned pseudonyms for the relatives involved to detail the family feud that saw daughter Mia sleep with her 20-year-old granddaughter's boyfriend.

Granddaughter Evelyn had since moved out of the home but the rift has been showing little sign of healing.

A woman has revealed how her family has been ripped apart after her daughter slept with her granddaughter's boyfriend (stock image)

The anonymous submission wasted little time in unravelling the sordid dilemma which had caused the family to 'blow up.'

The woman explained that Evelyn, who attends a local college, had been dating a guy but that the relationship had collapsed 'because she caught her boyfriend in bed with her mother.'

'Evelyn moved out of her mother's home and in with me, and has gone no contact with her mother. I am extremely disappointed and disturbed by my daughter's conduct. 

'But as mad and as disappointed as I am, I do want to continue to have a relationship with her, if only to get a clear answer as to why she did something so awful.'

To make matters worse, Evelyn had since 'been trying to round up the entire family to go no contact with Mia, and has adopted a very 'with me or against me' sort of attitude about all of this.'

The frustrated grandmother wrote: 'She's very young, and she was grievously betrayed. But it rankles to have a guest in my home telling me who I can and cannot associate with. 

'On the other hand, I sort of agree with her. This is the worst thing Mia's ever done. But it's not the first time I've been taken aback by something my daughter has done. 

'If it was just a choice of who I want to spend time with, Evelyn is the clear choice, but I resent her putting me in this position.'

The submission was met with a thoughtful response which began by warning the woman not to 'hold her breath' waiting for an answer about why her daughter betrayed her granddaughter.

It continued: 'Of course, you are the only one who can decide whether to cut off your daughter, and your granddaughter shouldn't be demanding that you do so.

'Tell Evelyn that you love her and are happy to have her stay with you, but you aren't prepared to become permanently estranged from your child, and that's your choice to make.'

The reply also urged the woman to talk about what might be at the heart of Evelyn's insistence on making her grandmother choose between the feuding parties.

'You seem to think she's being vindictive, but could there be something else going on here?' it read. 

The columnist concluded: 'Expecting people to cut off her mother as proof that they can be trusted might seem reactive and unreasonable. 

'But if it's really coming from a place of fear and insecurity regarding who she can trust, maybe you can talk about and try to address those underlying worries with Evelyn, even if you can't and don't want to cede your right to make your own decisions about being in contact with your daughter.'