It doesn't sound like the set of the original 'Blade Runner' was much fun to be on. Rutger Hauer kept improvising the script, the constant simulated rain made everybody wet and miserable, director Ridley Scott's obsessiveness with getting every shot 'perfect' was driving people to despair, and Sean Young and Harrison Ford couldn't stand each other. It sounds like the issue was mostly on Young's side.
According to people who worked on the production, Young complained to Scott that Ford's facial hair was 'tearing her face up' when they kissed - which, looking at Ford's face during the scenes, seems unlikely. That irritated Ford, and so every kissing scene from then on was fraught and difficult. Their major love scene was nicknamed 'the hate scene' by the movie's crew, because everyone involved in filming it knew that neither actor wanted to do it.