Complex sentence: Precious reassured him that their marriage was a sham and promised not to divulge the affair, but whilst Paul went to get a take-away for a cosy night in together, Precious packed her bags and left.
Split into simpler sentences: Precious reassured him that their marriage was a sham and promised not to divulge the affair. However later that night, whilst Paul went to get a take-away for a cosy night in together, Precious packed her bags and left.