Three children are to be removed from their family home amid concerns that their parents’ “open relationship” may have contributed to neglect.

The ruling by a family court judge makes clear that the hearing was concerned only with the impact of the parents’ unusual lifestyle on their young children, who are all under the age of five and will now be placed for adoption.

The application was made by social workers acting for Sandwell borough council in the West Midlands last August and was granted in October this year. The parents nor children have been identified.

Social services officials described the couple’s relationship as “open”, although both parents denied that was the status of their relationship.

The father chose to see other women and the mother had relationships with men she met online, the judge Elizabeth Williscroft explained in her judgment.

“The father had his own lifestyle outside the family home which plainly included going clubbing until the early hours as well as being involved with other people,” she said.

“In respect of both parents, the court is not concerned about their private lives and how they will conduct them unless it impacts on the care of the children – which at this time was neglectful.”

The Wolverhampton-based judge said the couple continued their “dysfunctional relationship” while living in the same house. “All of this must have been confusing for the children.”

She said of the mother: “It is plain some complete strangers have visited her house while the children were there to have sex with her.”

The father “didn’t fully understand either why the presence of strangers at the home meeting the mother for sex was worrying”, the judge said.

Social workers said the couple found it hard to supervise their children, and Williscroft added: “Mother was observed parenting ‘from the sofa’ and relying on others to keep the children safe from hazards.”

The judge concluded: “After balancing the possibilities of care for these children, my analysis is there are no realistic alternatives to meet the children’s welfare needs throughout their lives but adoption.

“I bear in mind and balance that each child has a loving relationship and attachment with their parents but has also been harmed by neglect and would be at risk of harm in their care.”