A MUM-OF-FOUR has been inundated with praise after admitting that she refuses to let her ex-husband's "affair baby" call her "mum."

Taking to Reddit, the anonymous woman, who is from the US, explained that she divorced her husband after finding out that he had cheated on her.

An anonymous mum-of-four is refusing to let her ex-husband's "affair baby" call her "mum."

She went on to say that the pair split up four years ago and share four children Joshua, 20, Cassidy, 16, Nate, 11 and Jacob, 8 - but added that she will not take responsibility for her his motherless daughter, who was the result of his cheating.

The woman explained: "He had an affair baby (Juniper, 3yoF) with the other woman but Juniper's mum passed away when she was 1yo.

Aside from my ex-husband and his family, she doesn't have anyone else because her mum grew [up] in the system."

She continued: "I tried once to take the three of them out when she was younger but it wasn't for me, I know she's blameless but I can't separate her from my ex's betrayal, so know every time I pick Nate and Jacob up I try not to engage much.

"If she says hi, I say hi back, if she waves, I do too, but nothing more."

However, over the years, the young girl slowly started calling her "mama."

The woman continued: "I've told her things like 'No Juniper, I'm not your mum', 'Call me [my name], I'm fine with that,' last time she actually ran at me calling me mama and began to cry when I didn't pick her up and took her with me.

She went on to explain how her ex-husband actually asked if Juniper could refer to her as mum, which she refused.

"He basically told me that seeing me picking the boys up, being affectionate and loving with them is confusing and hurting Juniper," she wrote.

"She's a baby and she doesn't understand what's happening, so he asked me if I could just take her with me for a few days like I do with the boys and maybe, over the time, let her call me mum."

"I said absolutely no, that I'm sorry for Juniper, but that I won't be playing mum with her and that I'm only keeping a relationship with both of them because of our son's."

The woman went on to note how he called her "heartless" - but it wasn't long before social forum users jumped to her defense.

"It’s a shame you can’t divorce him twice," joked one.

A second commented: "Exactly. He needs to tell Juniper about her mommy & differentiate that her brothers have a different mommy. Juniper is innocent in all this but OP is not obligated to parent her as she is not her mum or step-mum."

A third agreed: "She might as well charge a babysitting fee for what he's asking. Plus a fee for the audacity."

Meanwhile, another noted: "100% every time Juniper calls OP mom he doesn’t correct her on purpose. 50% chance that he’s encouraging it.