What would you do

My husband and I have been married for 6 years I say he’s gotten angrier after until after he got out of the military and we’ve moved to this small town but anyway lately if something makes him angry like he just got off the phone with ob and was angry and said I’m going to f**in murder someone he will say stuff like that. He’s never said it to me but I confronted him once after he compared murdering someone to our son spilling water in the car and saying sorry and he got upset at me saying it was just making a comparison and just got angry at me . I don’t know I’m kinda getting a little freaked out that it’s his go to sentence when he’s upset. How would you feel and what would you do.