So you want to treat me a dinner? Yes, it's on me.

请客/作东= stand treat “我”请客 = this is my treat to treat sb. to dinner = 请某人去吃饭。

- Would you like to have dinner with me? - My treat. 你愿意和我一起吃饭去吗？ 我请客。 一般不用stand treat这个词，也不用this is，直接my treat