He will often bring up the topic of how he’s looking for that special woman and will probably give you ‘the look’ while saying so.
He will also joke about his single life in front of you and add to that the fact that he’s not bringing up any women around you, it’s pretty clear whom he wants to be that special woman in his life.
And if by any chance some woman comes over to hit on him, he will play along until he sees that he has your attention and then he will turn her down.
It’s simply because he wants to see your reaction. If he sees a little bit of jealousy on your face, you officially made his day.
Plus him being rude will only turn you off, so there’s no way he will rudely reject any woman who hits on him.