Husband wants open marriage!

Hi, so my husband and I been married for 6 years and been together for 9, he is the only guy I've been with so now every time he drinks and a few times when he is sober he tells me that he wants an open marriage and that he is doing it for me not him. He says sex is sex but if you do it I just wanna know if he is better than me, he is giving me permission to be with someone else. He is a marine now so I do understand that sometimes he is too tired to have sex but most of the time he doesn't want to and he wants a child but if we don't have sex how can he expect me to get pregnant! He always says I'm sorry for everything I put you through, you are the best wife and I want you to be happy and I know you wonder how does it feel to be with another man. I asked him what happens if I decide to do it and I like the sex with the other guy more than with you and he said then you like it more so I said what if I catch feelings and he said then you catch feelings and we weren't meant to be. After he says that he tells me that he wouldn't know what to do without me. So I'm confused! I'm home all day everyday so I don't get out of the house at all if it's not with him.