Let's just say for the sake of argument that Duncan and Courtney were over before Duncan and Gwen had their first kiss.

Heroes Vs Villains: Duncan explains in a confessional that he and Courtney were officially over before he kissed Gwen and his "evidence" is that despite their kiss on the bus, they weren't officially back together. He also mentions that he didn't tell her that they were over prior to gim kissing Gwen because he didn't want to deal with her. In this or the next episode, Gwen states in a confessional that she and Duncan haven't been in a good place in their relationship lately, and let's say she says that their relationship has been getting boring and she is getting tired of his antics.

Evil Dread: When Gwen ignores Duncan's flirting when they arrive for the challenge, she states in a confessional that ignoring Duncan may increase her chances of making things right with Courtney. After Gwen's second attempt of making up with Courtney fails, Duncan laughs and jokingly calls her evil, but this angers Gwen, who states in a confessional that Duncan being insensitive is not endearing.

Saving Private Leechball: After Duncan switches to the Heroes, Gwen states in a confessional that it may be good that they are on opposite teams, but the states that the kiss he just gave her and his kisses lately haven't been feeling as good as they used to and she has a concerned look on her face. After Courtney screams at Duncan, Duncan states in a confessional that for a moment, he thought she was going to kiss him, and then he starts to smile. However, his smile turns into anger, and he states that he would not have accepted the kiss.

Food Fright: While on the log, Duncan asks Gwen what Courtney is saying about him. In a subsequent confessional, a concerned Gwen wonders why Duncan is asking her about Courtney. In Duncan's confessional, he claims he wants to know what Courtney is saying about him with somewhat an excited tone, but then he becomes a little mad and says he doesn't care about her. After the challenge, he asks her what Courtney is saying about him again and is more excited, but this annoys Gwen, who says she hasn't said anything about him. In a subsequent confessional, an annoyed Gwen says she is not liking that Duncan is becoming interested in Courtney again. Then, Duncan states in a confessional that he doesn't care about Courtney, but knows she's talking about him. Duncan then excitedly states she wants him back, but then becomes mad and says he does not care.

Moon Madness: Unlike simply asking Gwen what Courtney is saying about him in their first encounter, he tells her he knows Courtney is talking about him and tells her to tell him what she is saying about him. Gwen becomes angry and says that once again, she hasn't said anything about him. However, she does not insult him. In her confessional, she says that it is clear that Duncan is into Courtney again and that she will break up with him if he asks again. However, she accuses him of being interested in Courtney, instead of obsessed. Duncan still has his same confessional. After Duncan kisses Gwen and asked if Courtney saw at the elimination ceremony, an infuriated Gwen claims she cannot be with someone that is still into their ex and then breaks up with him. Gwen still has her confessional, but also states that she probably should have ended things before the season. In Duncan's confessional, he is shocked that Gwen dumped him and then states that he's not into Courtney, but then his eye twitches.

No One Eggspects the Spanish Opposition: In the confessional where Duncan wonders why Gwen dumped him, he instead states that Gwen dumping him was a mistake because he is not into Courtney, but then claims excitedly that Courtney has to want him back now, before denying he cares about her again.

Suckers Punched: Gwen does not mock Duncan. After the challenge, Duncan approaches Gwen to talk about their relationship ending. Gwen claims that she was losing interest in their relationship because everything's was getting too predictable and his antics were getting old. She then told him that what caused her to dump him was when he constantly asked her what Courtney says about him, which then caused a guilty Duncan to apologize for and admit he was wrong to do that. Gwen, however, forgives him. Duncan then agrees that everything was getting predictable and boring, even though neither would admit it. Gwen claims that she's not into him romantically anymore and Duncan says he feels the same way. He states that they would be better off as friends and she agrees, leading to the two fist bumping. She then tells him to go for Courtney because he's still into her, but he denies liking her.

You Regatta Be Kidding Me: Gwen does not believe Duncan's take at Mike being a threat but does not laugh at him. Instead of blowing up Chris's cottage which leads to his arrest, Duncan is voted out due to Mal rigging the votes. Before he leaves, Gwen wishes him luck and both expresses gladness that they are at least able to be friends.

Final Wreckening: All the contestants appear in the finale. Before the challenge starts, Duncan and Gwen fist bump each other and he wishes her luck. The two then state in confessionals that they are glad that they are friends again.

Conclusion: I think this is a good way for them to end. Tell me your thoughts.