Mark long dating
He also forms a friendship with Callie, and develops an attraction to cardiothoracic surgeon Erica Hahn (Brooke Smith).
Erica does not reciprocate his feelings, and he is supportive of Callie when she and Erica have a brief relationship.
Bumble was first founded to challenge the antiquated rules of dating.
The nurses later start a club against him called Nurses United Against Mark Sloan.Mark has a brief fling with Addison's friend, orthopedic surgeon Callie Torres (Sara Ramirez), and develops a friendship with Derek's girlfriend, intern Meredith Grey (Ellen Pompeo).