くさっちゃう
kusacchau

Godan Verb (ru)
Godan Verb (u)
Auxiliary Verb

The completive aspect (contracted form) - indicates completion or regret of 腐る

1. To rot; To spoil; To go bad; To become ruined; To be overdone (cooking); To fail; To be lost (opportunity)

Completed Action
Colloquial