It depends. I think the legal situation is that he needs to not see you for 2 years after he ceases seeing you in a professional capacity.

That being said, some clinicians are of the opinion that ethically it is always inappropriate for a clinician to date a person who they previously saw in a professional capacity.

Do you really believe in love at first sight? What do you mean by that? Lust that turns into love as you get to know each other? I don't see how one can fall in love with a person on the basis of a short encounter... You don't know about his sense of humour, his life plans, his religion, his background. He could be a compulsive gambeller or a workaholic or be a complete control freak... It might be that nothing serves to be a 'deal breaker' once you get to know him but I don't really understand how one could fall in love with a person when one doesn't have a liking for those kind of background things that you simply... Don't know anything whatsoever about...