He dislikes the guy. It’s easier for him to dislike a Sans than to like them cause... reasons. However he doesn’t hate Reds. He still feels guilt over his mishaps, but he tries to not make it too apparent since apologies will definitely get him nowhere with Reds, and that kind of upsets Vile. Again though, he tries to not make that too obvious.
If anything, Reds is just a minor annoyance, only ascending to intolerable-hood in a few situations. He knows most of the time it’s to get on other’s nerves, but Vile is SO TEMPTED to take that bait just to get in Reds’ face. Vile is just not good at keeping low in some situations... unless it’s directed at his fragments. He could care less about their feelings and is quite tempted to jump in and assist Reds in the assault, even if it’s likely to put Reds off completely.
During Reds’ little Be Nice M!A, Vile saw something else and it made him hope that maybe under all that bite and unexplainable anger, there is a good guy in there. Maybe he’s a little TOO hopeful though. He’ll likely never see that part of him.