someone's heart is in their mouth

US /ˈsʌm.wʌnz hɑːrt ɪz ɪn ðer maʊθ/
UK /ˈsʌm.wʌnz hɑːrt ɪz ɪn ðer maʊθ/
"someone's heart is in their mouth" picture
1.

kalbi ağzına gelmek, çok korkmak

to feel very nervous or frightened

:
When the roller coaster started, my heart was in my mouth.
Hız treni başladığında kalbim ağzıma geldi.
Her heart was in her mouth as she waited for the exam results.
Sınav sonuçlarını beklerken kalbi ağzına gelmişti.