Ok so I'm looking for this 80s or 90s movie in a big city, possibly New York. It's about a mom who has a son, and a dad who has a daughter, or the dad has the son and the mom the daughter. Anyways, one of the parents end up losing their kid, and I think it's the dad with his kid who finds the other kid. They spend the day together, and eventually they somehow find the mother. And then they fall in love? Does anyone know the movie? Thanks!