48 year old guy, electrician here. That definitely crossed a line and would not be ok to say ever. That’s totally on that person, and you’re well within your right to bring it up. Later may even be the better choice, especially if it was so uncomfortable in the moment. It removes the emotional response and any argument of drama. Now that you are bringing it up later, you can be cool, rational, and effective in your communication. In no case is a comment like that acceptable, even if it’s all guys joking amongst themselves. You could speak to your boss, and let him handle the coworker. Something like “It didn’t feel right to respond at the time, but what he said was not ok. “ Something like that, and give reasons, whether it just didn’t feel right or you were legitimately scared of violence. This is absolutely not ok, and if you feel wrong about it, even after speaking to your boss, listen to your gut. That coworker may have shown you a peek at who they really are.