I almost laughed at the title of this thread, but yeah, I've done that. My Dalish Warden had chosen the option to flirt with Tamlen at the end of the game. She only joined the Wardens because the Keeper said that she should. She felt obligated to stop the Blight so that her clan would be safe, but she was also kinda hoping the entire time that she would just get killed in battle already, yet for some reason, she just couldn't die.
I think of it kind of like the manga Berserk, where the main character is getting attacked, and he's prepared to die, almost relieved, actually, but when one of the wolves attacking him lunges at him, he instinctually stabs the wolf with his sword, killing it. His body forced him to live, even though his heart didn't want to. (I think waaaaaay too much)
Then, when she saw Tamlen, and knew that she could have kept looking, and maybe saved him, it killed her. When he said he'd always loved her, she just stood there as he attempted to kill her, hoping she could just die already. After Tamlen died, having said he loved her, that's when she decided that she couldn't keep living, and that one way or another, she would die once this was all over.
So when Riordan told her how the archdemon dies, she
immediately volunteered. When he said, "Oh, that's noble of you, but no, I will," she was basically like, "This isn't over Riordan."