HiCustomer Thank you for asking your question on JustAnswer. By the way, it would help us to know:
-What are your ages?
-How long have you been dating?
-Have you told him this bothers you?Thank you again for trusting us with your problem. Please reply as soon as possible so that we can finish answering your question.
A feew more questions:
-Does he suffer from depression or bi-polar do you know?
-When you tell him how you feel about it does he try to change afterwards?
-Do you know what kind of family life he had growing up and as a young boy?
Since it rarely happens then I would chalk it up to his depression along with stresses from his son's mother and he doesn't know where to channel that anger so he channels it on you. If he could learn to channel his anger at the real people or person that deserves it maybe he could stop using you as his sounding board he may not mean to treat you that way and since you said it rarely happens maybe you can talk to him when it happens and calm him down a bit, tell him you want to be there for him no matter what he is going through but you cannot be there if he continues to run from it. If it's so few and far between then maybe you could endure it and wait out the storm for the sake to keeping the peace there may be times he just needs to be alone and that is how he goes about getting that space. He also should not keep things bottled up to the point were he shows that behavior when he has reached his boiling point. Communication may be something he is not good at when he is angry and would rather go away and calm down and then things will be okay.