I've heard worse coming from my younger sister's lips and she's only 7. xD
Hmm... it depends, really. What kind of voice was the person saying the sentence in? If the voice tone was noticeably light-hearted, joking and warm - then it might've been just for laughs.
If the tone was deathly-serious, humourless and straightforward - then the person might have some serious anger issues. или Ты might've done something that really riled them up.
There are many things to consider....
How close the person is to you, whether they've сказал(-а) similar things to Ты before, whether they actually ever did any of those Назад things, what their history of violence/crimes/behaviours is...
Ты can confide in someone close to Ты and then see what Совет they can offer.
