Grey’s Anatomy's Alex Karev had one of the best character arcs on TV, which is why his dalliance with Izzy and hurting his wife was such a betrayal of his character. From season 1 to season 16, Alex grew from a selfish, angry bully to an empathetic and respected pediatric surgeon. He went from being the guy who papered a locker room with pictures of Izzy Stevens in her underwear in order to embarrass her to the guy Meredith Grey trusted with her children. Hence, Alex Karev's stunning Grey's Anatomy decision to leave Seattle, Grey Sloan, and his wife, Jo, for Izzy completely upended his growth.
Given that the relationship was seven years long (give or take some breaks), Jo deserved better than for her marriage to end so disrespectfully. Alex was low enough to end it in a letter: He had left her for Izzy, who had secretly had his twins three years earlier. This betrayal was completely out of character for the more mature version of Alex. While he could still be thoughtless, he tried his best to do the best he could for his found family at Grey Sloan. Even at his worst, he valued honesty. Yet, to the most important person in his life at that time, he lied and cheated. He left no forwarding address, and didn't take Jo's calls. This behavior seems less like he wanted to be there for his children, and more like he was having an affair with Izzy. Alex didn’t discuss shared custody of the children or any other possible solutions with Jo before making the decision to leave her.
Alex's Decision To Leave Jo For His Kids Makes Sense
In his letter, Alex justified his decision to leave without discussing any of it with Jo as they were his kids, and he had missed too much of their lives already. He framed the choice as one between hurting his children and hurting the adult Jo in Grey's Anatomy. This almost makes sense, given the way Alex was raised. His father was an abusive drug addict, and his mother wasn’t able to cope with Alex or his siblings because of her untreated mental illness. He had been adamant throughout the series that any kids he had would grow up with him. So when he found out he had three-year-old twins with Izzy, he did, of course, jump to be with them as soon as possible. He mentioned in the letter that he didn’t want to miss any more days, and that is why he had to go be with them.
But The Way Alex Left Jo In Grey's Anatomy Wasn't Right
However, Alex Karev ending it in Grey's Anatomy with a letter is exceptionally selfish. He told Jo that he was a coward for telling her this way, and that she deserved better, but that he was going to be with Izzy anyway. He said that he knew he was hurting Jo, but that he now had everything he always wanted. He stopped short of asking her to be happy for him, but it was heavily implied. He also said that he loved Jo, but was in love with Izzy. And yet, he said that if he had told Jo in person, he wouldn’t have been able to leave. Alex had never previously had a problem doing what he felt he needed to do, which suggests this was as much about Izzy as about his twins.
Alex and Izzy were two of the original Grey’s Anatomy interns, and have a long and tumultuous history together. At the end of Grey's Anatomy season 6, Izzy left Seattle Grace (now Grey Sloan Memorial) and Alex in much the same way that Alex later left Jo. Alex should have remembered how destroyed he was by that, and done right by Jo. Instead, he made a cowardly and selfish choice, and then tried to use his children to justify it. That is below even the low moral standards of Grey's Anatomy season 1 Alex.