ほころばしちゃう
hokorobashichau

Godan Verb (su)
Godan Verb (u)

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

1. To bloom/blossom (and regret it); To crack a smile (and regret it); To show (something) (and regret it)

Completed Action
Colloquial