He hasn't? What on earth has his mother been thinking? The blushing and fidgeting gets him another almost-sigh from Jack.
"Okay, let's leave sex out of it for the moment. I take it that's not something you've much experience of yet."
He thinks for a moment. "How about we just compare it to friendship. You can be friends with more than one person at the same time, can't you? Even friends who aren't friends with each other?"