It depends on the situation. I've still been cordial with people my exes ain't like especially if it was over small dumb shit but something major like someone fuckin over them or whatever, its fuck them.
Funny enough, I've had people not fuck with me because their s/o aint fuck with me or dislike me for whatever reason. We could've been cool af but bc they nigga aint like me, they stop fuckin with me. Then when they break up with dude, they come tryna be cool again, nah stay over there. You can't pick and choose when to be cool with me.
Shit's corny from the jump and I much rather we not be cool if your nigga not liking me causes a friendship to be ruined.