When the final four are trapped on an island, Duncan states in the confessional that it was great to be stuck on an island with two hot girls (referring to Gwen and Heather), before adding they're both "completely insane".After spending the duration of their time on the island arguing, Gwen makes a raft to get herself off the island.After Duncan quits the competition, Gwen shows signs of missing him and even mistakes a rock formation for him in Newf Kids on the Rock, which Courtney becomes suspicious of.Duncan also shows similar feelings to Gwen and begins to lose interest in Courtney (whom Gwen starts to be friends with) due to her control over him.Gwen picks Duncan as her first teammate for the Screaming Gaffers and their friendship causes jealousy to rise from their respective romantic partners, Trent and Courtney, leading to tension to arise in their respective relationships.Around the time Total Drama World Tour starts, Gwen (who had broken up with Trent last season) falls in love with Duncan, but feels very uneasy about it, as Duncan is still dating Courtney.When Tyler said, "At least you don't have to sleep next to him," Gwen looks intimidated by Duncan, who is seen giving a deer a noogie.
They become even closer friends in Total Drama Action, which slowly develops into an attraction, despite Gwen denying it at the beginning of the season.
Gwen asks Duncan if he could hold it after another ten chapters of a Canadian history book which proves to be too much for Duncan who surrenders and falls asleep in the bathroom.
During the rock climbing challenge, Heather pulls a prank on Gwen that causes her to lose her skirt while climbing the mountain, leaving Gwen with her underwear fully exposed to everyone watching the challenge.
Both Duncan and Gwen (along with Izzy) are the only camper to enjoy the gory movie that the other campers seemed horrified to watch.
After the movie, they realize that they share the same favorite horror movie and talk about their favorite gore scenes from said movie.