Just to follow up on my own post. Here is what I did:
I simply went after her, totally ignored the Orbital, at least on the surface, inside it was quite difficult. I went after her again and again, became decent friend with the Orbital, and yet kept stepping in physically between them (the guy is almost one head taller than me) and kept hitting on her - despite the fact they were kissing and hugging each other in front of me. It is really not as easy as it sounds, I almost gave up several times.
I never talked bad about him with her, rather the opposite, I described him as a great guy. She even tried to bad mouth him while with me, but I knew it was a trap. I never said one bad word about him, if I did I would lose the game. Later on she admitted that it was wise. Finally, Orbital lost his balls, he left the battlefield. He tried to come back several times, but he didn't have the balls to stay. Only me and her were left, I won. Later on she also admitted that she was in Love with him (which I kind of knew anyway), intensive platonic love. If they slept together, which I was anxious to find out so I don't look like a total fool, it could have end up differently.
She gave up on him because he didn't have balls to fight for her, despite the fact that she loved him and he loved her. She may not love me the same way she did him, but she is much more attracted to me. She, like any other woman, can't simply resist more persistant and dominant guy.
Bigger balls and persistance always wins...