I've been searching the Internet for stories, preferably at least partially true, about adult father and son relationships developing into sex. I haven't found any good ones. The "groundwork" was laid while the son (me) was a boy/teen but didn't develop into oral and anal sex until adulthood. My family situation now includes both my brothers as well as my dad. We are all over 37 yrs. old and the sex is only recreational. We are all married to women. None of us has a sex life at home that matches our drive so this family fun is a kind of a way to not "cheat" with other women. For example, none of our wives will give really good head anymore. The funny thing is, I think this is more common than most would realize or admit. We all know at least one or two buddies that occasionally plays with another family member or married buddy.