Art by @nprofile1q...

Before Kris and Liam ended up on Earth, their parents, Prime Minister Ritchie(brown haired boy) and his wife Eleanora (blonde girl) decided to personally educate their children in sexual interaction by performing the act in front of them. Needless to say, they’re both fast learners.

This also ensures that they’ll have more siblings should they also come to Earth from Sholia, as their race are able to reproduce very early.