9-
He'll become even more sarcastic then usual and will tell the guy flirting with you to shove it.
10-
The Doctor will death stare the person flirting with you, when he decides he's had enough he'll wrap his arms around your waist and place a kiss to your neck before glaring daggers at the guy once again
11-
He doesn't understand that someone's flirting with you to start off with but once he's caught on he'll become obsessive and won't stop hugging you. Sometimes he'll get very over the top and will publicly confess his love for you.
12-
He'll argue with the person flirting and make you leave, you find it funny when he gets jealous but he doesn't. He'll go in a huff for hours.