You don't accidentally do something selfish.

You intentionally disregard & ignore the rights, feelings, & dignity of another person to achieve a goal but would be livid if someone did that shit to you.

So you know you're disrespecting or harming someone else & don't care.

Then when confronted you lie and say it's an accident and hope they believe that bull shit.

Unfortunately most people do because they lack self-respect & tolerate that disgusting behavior because of emotional codependency or fear of losing you or whatever the insecurity may be.