<human>: Today was the first day of a trade show where I promote a companies apprentice program and encourage young folks to get the right job. At this fair there was a really sweet girl so I took the classic ninja approach and wrote her a letter on the back of our apprentice sheet. It just said: "Wanna grab coffee after work? Yes :) No :(" I walked up to her and gave her the letter, she opened it smiled and said I should definetly come and that it would be a blast. 

First success and maybe the last one. She told me that she had to work until 7p.m. and I waited three hours for her. She came towards me and we were having a nice chat. After a while she told me that she had to leave and had to go to the hotel. Only then when I asked for her cell number she realized that I was hitting on her. 

To me there came an epic reveal. Since it is a business event, there was a "get together" after the whole show and people were talking business. She totally did misinterpreted my intention to ask her out and blushed with her hands hiding her face, all in front of her colleagues. She was extremely embarrased and I guess she was blaming me :(. So basically the letter would have worked in any other occasion but not at a fucking business event were everybody is drinking coffee and shit -.-.

Thanks for reading, I'll cry myself to sleep now, because my coworkers all picked up the story and will laugh at me for being so stupid tommorow. (No matter how much praise I got for the ninja letter aproach)

Can you summarize the given text in a few sentences?
<bot>: Tried to ask a girl out. Asked if she would grab a coffee with me at a business event. Wasted 3-4 hours including the drive home, because everybody asks for bloody coffee at trade fairs.