If your S.O went to vegas several time without you without your knowledge while being together and also living together?

And/or having an argument with your S.O. and he goes to a bar but a lady answers the phone when you've been calling all night, he is at bar nearby our house? He answered after hanging up on the lady that it was the bartender figure of speech (I want to freakin kill him)

What would you do and how would you react? Please Imma go crazy