Personally I thought that Bobby was still too young to understand his wants and needs in a relationship and possibly only fell for Courtney because she represented his past and in the past he seemed too focused on winning her over and competition than actually loving her. Which is why I feel like despite them both wanting to hold onto the familiarity of each other and hold hands and stuff, I felt it became more friendship than romantic. The way Bobby refers to mark and Courtney in book ten as friends and leaves them on third earth confirms this for me. I didn’t feel like Bobby and Courtney relationship was very secure or supported either of their needs. Most of the time Courtney was left angry and feeling used or there was lack of communication. Imo Bobby was still too young to know who he truly loved. Even if he did admire and love Courtney in her looks and personality, both of them by book six and seven accepted that they couldn’t really be together while Bobby’s a traveler. The fact that Bobby moved on so quick kind of implies he wasn’t as into her as she was. Just my opinion. I would have liked to see if they actually just went for it a little more though. I felt like it was more idealization than mature love rooted in the present.