get above yourself
US /ɡet əˈbʌv jʊərˈself/
UK /ɡet əˈbʌv jʊərˈself/

1.
creerse superior, subírsele los humos
to think that you are better or more important than you really are
:
•
After his promotion, he started to get above himself, treating his old colleagues poorly.
Después de su ascenso, empezó a creerse superior, tratando mal a sus antiguos colegas.
•
Don't get above yourself just because you won one game.
No te creas superior solo porque ganaste un partido.