The reason being that his father was recently divorced at the time and they had sex once while both of them were under the influence. After that his father was so ashamed of himself that he decided to become sober & has has been avoidant towards my best friend ever since.
For further details:
Uh… that’s fucking wack. But okay.
They don’t want to end up like their english neighbors.
A nation which legislates against fathers fucking their sons?