You've done tons of these cultural exchange programs, all over the world. It's actually a big part of your own culture, to spread the word. About free-use. And every time, the host mom acts all offended...until you pull out your huge cock, and tell them what their own sons said about them. About how you've been texting each other, back and forth, talking about all of this. Especially about her.
Then, they get all flustered. And then, they get excited. When you tell them that their dear sweet son is already balls deep in your own mom, filling her with cum, engaging fully with their "cultural exchange?" Well, it doesn't take long before they're bouncing on your big dick, begging for a huge load!