Dennis is the boyfriend of Mary Parkman.
Dennis made breakfast in bed one morning for his girlfriend, Mary Parkman. Later that day, she started having severe abdominal pain, so she went to the hospital. Her abdomen was distended and she vomited. They did a barium swallow study, which showed what looked like a bowel obstruction. They hoped it would resolve itself, but April found a worm in the vomit just as they saw a worm come through Mary's NG tube. She had intestinal roundworm and needed surgery to remove the worms. This disgusted Dennis and he made an excuse to leave. Mary was not surprised as she admitted that it was very gross. Mary's surgery was successful and she was stable and awake afterward. While she was in recovery, Dennis came back and apologized for leaving.
He is dating Mary Parkman. They've been together for a few months, but their relationship progressed quickly.