<human>: There is this girl at my school, I really liked. The whole year I thought she was single. So every once in a while I ask if she'd want to go on a date with me. She would say no. 

I fucking find out that she was dating the whole fucking time, (she broke it off 3 weeks ago). She's a private individual so I get that. I don't mind that she dated. Why didn't she say she was taken. She was being honest.

I don't know what to do. My sister says to snub her. Whereas others say, it's alright. I feel like she lied to me. Did she? What should I do?

Give me the gist of the text in a nutshell
<bot>: My crush acted like she was single for a whole year. I found out today she became single 3 weeks ago. What should I do?