It's logical, Aron wanted to take revenge on David with Alice, he paused because they went to the hotel, Aron doesn't feel attraction for Sara yet, he's just angry with her, and when he saw Alice angry with her mom, he probably thought that Alice also knew about David and that she felt the same anger he did. If Alice rejects Aron and doesn't want to take revenge, Aron will feel more frustration and anger. David prevents him from being with Alice and now he also returns home, and it's certain that he wants to be with Sara again, but this time Aron will be more attentive to his mom, preventing their encounters from happening, and Alice will also prevent those encounters.