You know you've missed your timing with a potential love, when they say things like, "I'll talk to you here, 'cause I have to. But if I ever saw you out, I wouldn't give you the time of day." And - "I wouldn't care if you died tomorrow."
So, if someone's sweet on you, and you don't respond to them when they come-on to you, and you wait too long to flirt back, you're just simply too late. They have already felt that you rejected them by not responding in a timely fashion - and now they're just plain mad.
However, you really shouldn't take it as a rejection because their present anger merely confirms just how much they liked you before you blew it!
Have an awesome day!