もったいぶっちゃダメ
勿体ぶっちゃダメ
mottaibuccha dame

Godan Verb (ru)

A casual prohibition ("not allowed to...") of もったいぶる

1. Don't be pretentious.; Don't put on airs.; Don't be affected.

Casual Register
Prohibition
Colloquial
Usually Written in Kana