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Here is a tough dating question--when should you call a girl after you've gone on the first date?
I surveyed many straight women I know and they all said the same thing: They will not go on a second date with a guy if he does not call to make sure she got home safely on the night of the date, and the next day to say hello. While I have often heard the urban legend that women think men who call the next day are desperate and a turn-off, all the women I know say that calling the next day is the most basic requirement if you want to go on a second date.
If you wait two or more days to call a woman back, she will assume you are not interested, you are playing the field with many women, or you are playing games. So they will not go on a second date.
I was always the eager little dater and called back the next morning, usually around 10 or 11 in the morning. You may want to wait until the afternoon in case she wants to sleep in or goes to church (let's say it's Sunday). My advice is to call back the next day whether you liked the woman or not. If you do not want to see her again, find a polite way to thank her for the date but tell her you cannot see her again. If you do want to see her again, be yourself and say you had a good time. Ask her when she is free to see you again.
Everyone seems to advise not to be overly desperate. Proceed at all times as if you will be fine if dating her does not work out.