How do I not piss people off when I apologize? How can I work on it?

Recently, my S/O and i got in an arguement because I had made a joke that upset him. He told me later that day that he didnt like that I made that joke and I said im sorry. Bur after, I said “I thought it would be ok because you make jokes like that all the time.” That pissed him off and we got into an arguement because he said i can never just apologize and theres always a “but”. After looking online because I really did want to know wether that was a bad thing to do I learned it takes away sincerity from an apology to to that. I wasnt trying to “beat a dead horse” or instigate anything at all, I was just trying to explain why I initally thought it was ok. How can I work on this problem? Whats the best way to apologize to someone without making it a “bigger deal?”