cream (someone's) pants

Translations
очень сильно обрадоваться или удивиться
He nearly creamed his pants when he saw the surprise party.
Он чуть не обрадовался, когда увидел сюрприз-вечеринку.
Definitions
A vulgar slang expression meaning to ejaculate in one's pants, usually as a result of sexual excitement or arousal. It is often used in a humorous or exaggerated way to indicate extreme attraction or excitement.