What's a giveaway that someone isn't a good person?

When telling you about issues in their life and everything is everyone else’s fault/ no accountability

How someone treats another person based on their job title. Anyone who treats a server, maid, garbage person, etc like crap is just telling the world how much a piece they are.

When you express a boundary, they try to guilt trip you, pressure you, or threaten you to try and force you to do things you don’t want to do.

Treating people well only if they can benefit from them in some way. If they treat you well, but treat random people like shit, they aren't good people. And they'll treat you like shit too if you ever stop being of use to them.

If they brag about how they pulled a fast one on other people. As if to say how smart/slick they are and everyone else is stupid.

They never apologize.

It's always about them. They're always the hero or always the victim in their stories.

Can't take criticism but probably dish it out to everyone else. They're never wrong.

They remember you are their friend only when they need something from you.

Nothing is ever their fault.

They constantly say or do things where their only justification for doing so is "It was just a joke" when called out on it.

When they cannot bring themselves to celebrate someone else’s success.

A lot of times they’ll straight up tell you. Anybody who gleefully tells you “I’m such an asshole” or “I’m such a bi*ch” is usually not joking, even if they say it while laughing.

Throwing trash out of a car window, littering

Treats animals poorly

So this should be obvious but it's not. As a guy, don't trust another guy if he cheats on his spouse. If he'll betray the closest person to him, he doesn't care about his friends either, trust me