How many movies have Billy Lau Nam-Kwong and Tiffany Lau Yuk-Ting acted in together?

They have worked on 4 movies together! Their first movie together was The Inspector Wears Skirts II (1989) while their highest rated movie together was Mr. Smart (1989). They have not worked together since Here Comes a Vampire (1990). They are most known for their comedy films together.