He wasn't stupid.
If Xander had called him and Veronica here and he was still acting like this, then it could only be to completely suppress Veronica showing her that her family couldn't help her at all and what made it even worse was that it was all true.
For his own and his family's sake, he could only turn a blind eye.
Besides, isn't Veronica Xander's fiancé?
At the end of the day, isn't this just a domestic incident?
It would be better for him not to interfere and let them solve it themselves.
Whether he truly believed that or whether he was looking for a way to comfort himself, that was what he was going to do anyway.
Veronica clearly saw Louis Avoiding her eyes and quickly realised that there was no hope that she would be getting any help from this cheap brother
Knowing this, Veronica just looked away.
Her brother wasn't the only person there, but Veronica had even less hope of finding any help from him.