Complex sentence: Some of the humour was built around her portrayer's 15 stone figure; when joining the series Adele happily signed the nudity clause present in all cast member's contracts reasoning that she would never be called upon to strip.
Split into simpler sentences: Some of the humour was built around her portrayer's 15 stone figure. When joining the series Adele happily signed the nudity clause present in all cast member's contracts reasoning that she would never be called upon to strip.