Kyle Booker is the wife of Sylvia Booker.
Kyle's wife, Sylvia, was diagnosed with a large brain aneurysm that she was told was inoperable. This caused them to re-evaluate how they'd been living their lives.
While dining out at a restaurant, Sylvia began to fellate Kyle under the table. Because of her aneurysm, she clenched and bit down on his penis. He then reflexively grabbed a fork and stabbed it into her neck. They both went to the ER, where Kyle was given and ice pack and the fork was carefully extracted from Sylvia's neck.
When they were looking into possible causes for Sylvia's jaw to have clenched, Kyle mentioned her aneurysm, which she hadn't told them about. They got an MRI and Derek Shepherd told her he could do a double-barrel brain bypass to clip her aneurysm. Sylvia had to be convinced, but she decided to have the surgery and it was successful.
He is married to Sylvia Booker. They both said that they had drifted apart until Sylvia's aneurysm brought them back together. They started traveling together and enjoying their lives. Before Sylvia's surgery, she made Kyle promise that they were going to quit their jobs and move to Paris and she said that if she died, he should do it without her.