Blair. Months later, Kevin is overjoyed when Kelly presents him with their apparent son. After their child's birth, Kelly and Kevin soon begin a messy divorce proceeding and custody battle, made all the worse when Kevin's son, Duke, arrives in Llanview in 2004 and sides with Kelly in the separation. Kevin wins custody of their son, but when Kelly divulges the child's true paternity, her hidden miscarriage of their child, and desire to return the child to his birth mother, Kevin becomes determined to keep the child known as "Ace Buchanan". Kelly eventually convinces Kevin to give their adoptive child to his birth mother, and the two end divorce proceedings and reconcile. Kevin is happy as him and Duke begin to bond. Kevin and Kelly are looking forward to their future together when Kevin becomes ill. The illness leaves Kevin sterile just as Kelly. Kevin and Kelly find themselves getting into arguments and eventually break up. On the day of the wedding of Michael McBain to Marcie Walsh, Kevin and Kelly have a severe argument at St. James Rectory and Kevin walks out on Kelly, leaving her weeping. Kevin learns Duke had comforted Kelly after their blowout, leading them to have sex before a freak tornado led to their being buried alive. When both Kelly and Duke are wheeled in needing surgery for severe injuries, a lack of available surgeons forces the next of kin of both Kelly and Duke, Kevin, to choose which one will be operated on first. Since Kelly had ostensibly suffered worse injuries than Duke, Kevin chooses her and is soon devastated when Duke dies before the operation. Kevin initially blames Kelly for Duke's death but grows more distraught when he learns that Kelly is pregnant with Duke's son and his grandson. Kevin eventually comes to terms with Kelly's pregnancy and is present when she goes into early labor. After the birth of her son, Zane Buchanan, Kevin asks Kelly to come to London with him and allow him to raise his grandson with her. Kevin returns on August 16 and August 17, 2007, to attend the funeral of his adopted grandfather, Asa. Kevin welcomes his cousin Matthew Buchanan to London when Matthew's parents Bo and Nora take him there to attend boarding school. On March 2, 2010, Kevin appears on Dorian Lord's doorstep to console Kelly about the death of her mother and Dorian's sister,