In Ghostbusters: The Ultimate Visual History, Ramis is quoted as saying: ‘The idea behind the scene was to give Dan a love interest — a woman who’s been dead for a hundred years.

Sexy Ghostbuster Costume – Smiffys

If these annotations are indeed Aykroyd’s, it seems like he was really into the scene — judging by all the ‘holy cow’ ‘whoa’ and ‘wow’ going on. Aykroyd remains adamant to this day that the scene was not just a gratuitous, sexist bit of movie banter, but based on real events he’d learned of from paranormal explorers. The raunchy scene was supposed to be part of a longer segment with Aykroyd and Harold Ramis, but was eventually shoe-horned in as a dream sequence due to run time contraints. This didn’t stop it making the final cut. Keen to stay true to the movie’s spirit and to maintain the delicate character arcs, director Ivan Reitman and his cronies ensured BJ was retained anyway. Hooray.