Gotta be honest, I love Cat and Lawson. I understand people's issues with it, but look...
He decided to go on BB. It's an intense situation where you're locked up in close quarters for three months, with no contact with your partner, in intimate friendships with other women. He had to have thought about the possibility of something like this going down.
Also, Lawson is 23 years old. How many people end relationships, no matter how serious, at 23 -- especially when they're going through such a huge, life-changing experience.
In my mind, I give something of a pass for people in the house. Obviously if he and Cat were friends outside and this were happening, he would break up with the girlfriend. He has no way of contacting the girlfriend, and while he's tried to push it away for the time being, it was going to emerge at some point. It's unfortunate, but he knew that going in.
I think they're genuinely a good couple, and that they are both being honest about where they're at. Especially Cat. She's mature, has been married, etc.
Unpopular opinion, I know. Sorrynotsorry.