I am not making this topic in the bugs forum since I don't know if it even is a bug or glitch, but here is the issue I am having:

I just recently completed MacCready's personal quest, Long Road Ahead, during which time he had conversations with me and even had an opportunity to flirt with him. However, during this time and even after finishing the quest, I don't get messages saying whether MacCready liked, loved, disliked, or hated an action. Therefore, I am unable to tell if I am raising his affinity, and am keeping him as a companion until I've somehow maxed it out.

Has anyone had this issue before? Or know what actions will max out his affinity?

That's weird. Are you on PC? You could check his affinity with console commands, if not, just keep stealing stuffs and see if it maxes out his affinity.

I'm on a PS4.

I just finished McCready's quest on PS4 and didn't have this bug. The one I have sort of killed the game though. His perk is bugged to give you 2000%, not 20% accuracy. This pretty much ruined by sniper build by making the game a cakewalk on any setting. If I had to do over again, I would have skipped McCready altogether until they fix this.