Behind the Yellow Line (1984)

Leslie is Simon, a mild mannered guy starting a new job and taking care of his mom and dad. He catches a glimpse of a pretty girl named Monica at the MTR station--and it's love at first sight. But she's going through a tough breakup with a guy who's married. She does get over it and the two become a couple. But not only does her ex return, Simon is constantly interrupted by a perky rich girl Anita, who spends lots of money on him, is annoying, but is just looking for company. This strains Simon and Monica's quest for love, but finally she puts Simon to a test, once again at the MTR station.