Back in the day it was common practice among British people like you. The chances are your grand grand grand......probably did the same thing.
British people like my ancestors didn't have the luxury of a Messenger from the supreme source of morality in all creation to warn them of the physical, mental & emotional harm having sex with children could do. What excuse did Muhammad or the Muslims have?
If you're referring to ancestors older than grandparents the correct convention is to use 'great'. So my grandparents' parents are my great grandparents. And my grandparents' grandparents are my great great grandparents and so on.
We Britons don't hold our ancestors up as moral exemplars for all of humankind to emulate unlike Muslims with Muhammad. Oh and you don't get to excuse Muhammad's immorality by comparing him with the immoral heathen. Doesn't work that way, I'm afraid. You've put Muhammad up on a pedestal so stop trying to use the actions of everyone who, according to Islam, is morally beneath him to justify his failings.
Who is actually emulating him marrying to 13 year girls? What are the chances of that? The chances are next to 0.
You're kind of missing the point here but before I correct you I'll address this question.
This guy,
this guy,
multiple people in Iran,
multiple people in Pakistan &
Saudi Arabia. I could go on but I think the point has been made. These are merely the newsworthy items but they're not exactly isolated cases either; they're also national legal systems determining the matter according to Islamic law.
And the point I was making was that if you're going to throw accusations of sexual misconduct like 'sodomy' around, you'd better make sure your own religious tradition is squeaky clean; especially when your faith's most revered figure had sex with a child.