Complex sentence: Over the next few months, Denise and Jon became closer, but in April 1995, when he made a pass at her, he was put down in no uncertain terms, and he walked out on both her and the salon.
Split into simpler sentences: Over the next few months, Denise and Jon became closer. But, in April 1995, when he made a pass at her, he was put down in no uncertain terms, and he walked out on both her and the salon.