This is my favourite thread for ages.
"I dated a guy who's penis really stunk when he was excited or pre-cum was noticeable at the tip. It was so foul smelling it almost made me gag"
"poop on ur dick. the poop smell should mask the fish smell."
I am thinking you need to be concerned instead of excited?
http://www.steadyhealth.com/Fishy_smell_from_precum_in_penis___Is_this_an_STD__t82065.html
http://answers.yahoo.com/question/index?qid=20120218171608AAmwKGw