It was a story about a guy and how his first love got married and
ended up getting married to a woman and together they had a son who imprinted on him and chased after the MC ever since then.
This was a very young handsome guy chasing after a much older guy.
http://www.mangago.me/tag/father+x+son/ see if you find it here..

It was a story about the main character being completely in love with his best friend who ended up getting married to a woman and they later got a son together. The son of his best friend ended up imprinting on the MC in his childhood which persisted even up until he was a grown up.
The main character has visibly aged with wrinkles around his eyes and all that but the son who is now around 20 yrs old is still chasing after him! It's a somewhat short story about a young handsome persistent guy head over heels all throughout his life for his dads best friend who is always reminded of his best friend when he sees his friends son.
I Will read this!! But i am still looking for that missing manga and thank you for suggesting this! Ive looked in The yaoi section till page 95...
Im pretty sure its this one
http://www.mangago.me/read-manga/winter_that_year/
Thank youuououououoouuouououoyoyoyoyoyououououogkfjgogkglgogkgognfpdlsog9riwks9so
Is it this one? http://www.mangago.me/read-manga/ai_ni_chimayoe/