A lot of my gay friends would, for no real reason, hate on straight people. This was years ago when we were still figuring ourselves out and some of us had recently come out (12+ yrs ago). I would rationalize it as them (teenagers/young adults rebelling) just wanting some 'pay back' on the general straight population for the years of prejudice against LGBTQ+. But luckily, they never acted on it, they grew up and got better and more accepting. Heterophobia is still a serious thing and would warn against dismissing it.
Now, if OP's gay friend was genuinely offended by OP's actions, then he is absolutely entitled to being upset. But I would hope there was some misunderstanding or some insensitive questions asked that with clear, genuine and honest non-hateful communication could clear up.