open relationship question ?

SO holds against me asking about a open relationship! now he says since i ask that i must be fucking the man. This happen 7 mos ago been together 8 mos ... so ever since then he has never trusted me! I don't think that's right bc the question wasn't that deep and i have never cheated or shown him I will cheat! Does he have the right to hold that against me and not trust me ? or am I wrong! Btw ever since then I have tried to build the trust , change number , deleted social media , phone password everything! I am a open book!