Here is a great video explanation to answer your question. And to answer it myself, yes, it would. It is called classical conditioning originally discovered by Pavlov with his dog & food study. The video show is a funny but good explanation of how CC works and to finish up the answer, the man would be able to uncondition himself but it would be very hard. The best way to reverse the conditioning would be for the girlfriend to put up her hair and not allow sexy time and eventually the conditioning will fade.