Responses
Well I think it was more like Ryou's dad was Kogami's unrequited love, seen as Kogami is now 37 years and Ryou just started university (around 18-20 years old) it means Ryou's dad fathered him around the age of 19 (well he could have been bisexual ;)...)
Man, don't tell me that his father and the doctor used to be lovers... It'll be really awkward ..