Complex sentence: Beatty and Kilpatrick, both married at the time, to other people, did discuss city business; however, many of the series of messages describe not a professional relationship but an extramarital sexual relationship between the two, often in graphic detail.
Split into simpler sentences: Beatty and Kilpatrick, both married to other people at the time, did discuss city business. However, many of the series of messages described not a professional relationship but an extramarital sexual relationship between the two, often in graphic detail.