Lars was always a dick to Sadie. He was constantly using her and taking advantage of her feelings for him. He pussed out during their space kidnapping and left her to die. Even after his redemption during his time in space, he was still upset at her while reading the letter update because Sadie was where HE wanted to be (successful and hanging with the cool kids) and how it she must have wanted to hurt him. It was just always about Lars in Lars' head. Sadie wasn't someone he respected or wanted.
Sadie saw that she wasn't getting as much back from Lars as she was giving him, so she closed and locked that door and moved on. She said it was "so much easier" being with her new partner and that she was happy. This was probably a direct jab into Lars' side, because she was constantly fighting for his acceptance and attention and she didn't have to fight with this new person. The person actually WANTS sadie in their life.
Lars will hopefully learn his lesson and not repeat this in the future. Either that, or as
>>112211484 said, he's just gonna go out and play space-pokemon and try to catch every venereal disease in the galaxy. Either ways - Sadie deserved better and now she's got it.
