Closest I saw was her thinking "I'm playing a dangerous game here" after she cheats on him once more (well, a couple of times more, during the full episode...).
There's a scene where the couple she babysits for turn up during a picnic and you can make the choice for them to join Victoria and Lucas for a chat. If you choose that, I think with no further choices, it ends up with Victoria getting groped by the husband, leaving to go to the toilet, and masturbating. The husband goes to check on her and fucks her, while the wife gives Lucas a handjob, and although I didn't see them being able to see it, dialogue tells us that Victoria and the husband could see the wife with Lucas through the window. So I suppose that could give an opening to some separation, but the way the game is going, I would be surprised. It seems that having Victoria cheat on Lucas is too much of a draw, so they'll never break up.