Sounds scary......I and incest don't get along very well but I'm strangely intrigued and might not mind getting to know what manga this one is.
Not sure.. It's the one you're looking for. They divorced by taking one son.
http://www.mangago.me/read-manga/tsumibito_no_kiss/uu/tsumibito_no_kiss-chapter-3
I think i know that one the father is about 40 ? And he and his son adore the little guy too much and then hit it off with him but can't remember the name
Yes thank you this it
This story is about a dad and his son when his second son was born he ran off with the first son. Years later the mother dies and lives the second son in the fathers care. The first son and the father fall in love with the second son. Any thing ring a bell