I met them as an already married couple and everything seemed fine until she went into labor at my house. It was her second child so she knew it was early labor and decided to rest on our couch while we hung out. We were going to watch her older child when she went to the hospital anyway and our house is 30 minutes closer to the hospital, so it made sense for the three of them to hang around our house until "go time." That's when my husband and I started noticing her husband's strange behavior.
He was a very charming guy and a very good father to his son, but he started making fun of his wife during contractions. He would roll his eyes and tell her to shut up if she even made the slightest groan. He joked that she was a p**sy and was overreacting. The whole situation got so awkward that my husband insisted he go home to get their hospital bags, just to give the poor woman a break from her crappy husband.
A few months after the birth of her second child, he hit his wife with his car while she physically tried to block him from leaving during an argument. He disappeared for days and didn't come home until she proved to him that she hadn't gone to the hospital or contacted the police. Thus began systematic abuse that continued for two more years and she hid from me like an expert. He would hurt her and then threaten to withhold money for groceries if she said anything to anyone.
I knew he was a d**k and I knew she often needed me to pick her up to get food from food pantries because "he was bad with money," but I had no idea he was hurting her. She finally left him after he threw her through a window while she was eight months pregnant with their third child.