YOU SAID:

So yesterday I was hanging out with my friends when suddenly one of them started singing let it go and the other one slapped him in the face.

INTO JAPANESE

だから昨日、友達とぶらぶらしていて、突然一人が歌い始めて、もう一人が彼の顔を叩いた。

BACK INTO ENGLISH

So yesterday I was hanging out with my friends, suddenly one started singing and the other hit his face.

INTO JAPANESE

それで昨日友達とぶらぶらしていたのですが、突然一人が歌い始め、もう一人が彼の顔にぶつかりました。

BACK INTO ENGLISH

So I was hanging out with my friends yesterday, but suddenly one started singing and the other bumped into his face.

INTO JAPANESE

昨日友達とぶらぶらしていたのですが、いきなり一人が歌い始め、もう一人が顔にぶつかりました。

BACK INTO ENGLISH

I was hanging out with my friends yesterday, but suddenly one started singing and the other bumped into my face.

INTO JAPANESE

昨日友達とぶらぶらしていたのですが、いきなり一人が歌い始め、もう一人が顔にぶつかりました。

BACK INTO ENGLISH

I was hanging out with my friends yesterday, but suddenly one started singing and the other bumped into my face.