Dating is for fun. Courting is for marriage.
Traditionally Courting would include no sexual activity but today that is not usually followed.
To have an excuse to not be "dating"....yet still routinely boning. A way to subtly deflect impertinent questions with sarcastic humor via archaic terminology without offending the one with whom one bones.
"Dude, I saw you with that girl last weekend. What's up with that?"
"What are you talking about?"
"Are you dating?"
"Nah, we're just courting."