If he was mad about lack of sex, it makes complete sense - the expectance of sex is now gone as he doesn't see you as a sexual partner anymore and therefore it's easy (easier) to interact with you. I work the same way, if my partner says no to sex few days in a row, I automatically start pulling away, am not interested in spending time with them anymore, start to feel less empathy for them in general etc. If your brain is wired so that sex = a big part of love, there's no reason to care for the person who shows you that they don't love you enough to show it. That doesn't mean I can't continue being friends with that person when the expectance of sex is taken off the table.