Do Mr. Gar and Carol have romantic history together?
I say yes, because in the episode T.K.O. when Gar spills the beans that he loved K.O.'s mom, she said "Not that" instead of being all shocked and surprised. This implies that Carol knows what Gar means by that, but it could also be Carol trying to quickly calm (Turbo) K.O. down and didn't have time to talk about Gar-loves-Carol nonsense. Maybe he could be K.O.'s unknown father that has been lurking since the episode "My Dad Can Beat Up Your Dad" (but maybe not).
As such, these are just my own thoughts, so comment on this if you thought this was helpful or if you want to add to this thought.
(P.S. I have seen the episode "Face Your Fears" and I know they were both in a group known as POINT.)