It'd started when while on patrol you'd found a baby abandoned in an alleyway, You should've left it at a hospital for it to get proper care and maybe even parents that know what they're doing, but Booster had begged and pleaded to at least try. So instead, you went through the process of adopting the little girl, which Michael was ecstatic about. Booster had spent weeks turning the spare bedroom(your bedroom) Into a nursery for the kid, so now you and Michael shared a room, were raising a baby, and for some odd reason it was kind of nice.
You'd come back home from work to find Michael grinning ear to ear as he sang softly to the little baby girl in his arms, it was surprisingly wholesome. You stood there and watched for a while as Michael doted on the infant, finally he noticed you and took the baby's hand to make her wave at you,"Say hi."He whispered to the baby.