Illustration by mileanme via Wikimedia Commons. I'm not sure if guys know this or not, but flipping a girl over mid-sex is a fraught act.
You asked: "Why do girls like sex from behind? For much of the last couple of hundred years or more, Western civilization has gravitated toward what we now call, "the missionary position".
To send her into outerspace with gushing orgasm after orgasm?
For starters, we had three things: a phone, an iPad, and a raging horn.