Being selfish or self-centered; putting one's own convenience or desires first without considering others.
彼は自分勝手な行動でチームに迷惑をかけた。
His selfish actions caused trouble for the team.
子どもが自分勝手に振る舞うのは成長過程の一部だが、直す必要もある。
Children acting selfishly is part of growing up, but it should be corrected.
自分勝手に決めないで、みんなで相談しよう。
Don't decide on your own; let's discuss it together.