Emma Thompson who played Professor Trelawney was married to Kenneth Branaugh, aka Professor Gilderoy Lockhart.
During their time on set, Kenneth had an affair with Helena Bonham-Carter, who you will know as the incomparable Bellatrix Lestrange.
Emma found out about the affair which lasted about five years, and eventually got divorced. But interestingly enough, Kenneth and Helena actually met on set of Frankenstein in 1994.
Emma spoke up about the affair for the first time in 2013, revealing that it was all "blood under the bridge," saying that, "You can't hold on to anything like that. It's pointless. I haven't got the energy for it. Helena and I made our peace years and years ago."
Helena and Kenneth's relationship lasted for five years before they split, and Helena later started her long-term relationship with Tim Burton.
Harry Potter is lit fam.