Soldato
Don't wanna justify anything just wanted a discussion on it that's all. Bored and in a ethicsy mood.
Well on a more serious note then, here's my reasoning;
You have a "natural" relationship with your mum which should stay that way. As soon as something like that happens it turns into a completely different type of relationship, one that's completely unnatural and can't be good for you!
It even shows that nature is "right" because you're likely to get a pretty deformed baby if you try and prove otherwise. Contraception or not, it's immoral and against the kind of relationship that's natural or mentally 'healthy' to have with your mother.