help me pls

Alright. This summer i finally enjoyed life. Enjoyed the single life. Enjoyed myself. And this dude decides to message me on Tinder and saying he was looking for a serious relationship. I went out with him a couple times and guess what? Ive fallen for him. It all sounds great however hes been acting so tired when we text and never flirts over texting. I asked him if he was still interested and he like was surprised id even ask that. Like ladies please help me. How do i play hard to get here? I dont wanna get hurt. I want to be official with him but why is he like being so damn dry?!? I think he thinks he got me. Teach me how to play hard to get so i can make him nervous and maybe finally he will flirt again!!!! Im going crazy.