Cersei and Jaime's twisted, unhealthy relationship has been a constant on Game of Thrones ever since the very first episode. Their warped devotion to each other is a lifelong thing and while it has led them to inflict all manner of cruelties on each other, neither seems able to free themselves of the relationship. Cersei's ascendance to the throne might be the very thing that begins to splinter their bond irreparably, at least based on the look Jaime gave her in the Season 6 finale, but something else might get in their way. Is Cersei getting a new love interest on Game of Thrones?
It wouldn't be terribly surprising if she did, because Cersei has had other love interests in the past. She had little choice when it came to marrying Robert Baratheon so he doesn't really count, but she did engage in a second incestuous relationship with her cousin Lancel Lannister. Cersei does whatever she has to do to meet her own ends, so if a relationship with someone else would benefit her, it stands to reason that she would at least consider it. That possibility becomes even more likely if her relationship with Jaime continues to be strained; she only turned to Lancel because Jaime was gone, after all.
There was also a very interesting comment made by Nikolaj Coster-Waldau during an interview with The Daily Beast. When he was asked about the scene where Jaime confessed his love for Cersei to Edmure Tully as an act of manipulation, Coster-Waldau said, "[Jaime] knows about people's weaknesses and loving someone unconditionally — because he loves his sister unconditionally. Plus, there are no other suitors. Well, that's not true... but he has to step up and take his father's place. Wow, I was about to reveal something from Season 7 and thought, 'What am I doing?'"
Coster-Waldau's potential slip-up certainly makes it sound like someone else will be vying for Cersei's attention this year, which fits in with a fan theory that is becoming more and more popular. Many viewers think that the new leader of the Ironborn, Euron Greyjoy, will try to solidify his power by forming an alliance with Cersei. Pilou Asbaek, the actor who plays Euron, has mentioned his character's desire to meet up with Cersei in interviews, so it seems plausible that their potential alliance could become romantic.
Still, even if Cersei does have another love interest, it's hard to believe that she could actually care about someone besides Jaime. She may be with someone else for political or personal reasons, but so far nothing has been able to shake her obsession with her brother. It doesn't look like anything ever will.