AITA for accidentally insulting my boyfriends intelligence

So a little backstory: I (23f) and my boyfriend (22m) have been together for 6 months. A fairly new relationship but it’s been really nice and we get along very well. Honestly, one of the most genuine connections I’ve had with anyone. However, we’re starting to leave the honeymoon phase and are finding things we disagree on and all that.

The incident happened last night. One of my best friends was performing guitar and singing at a bar so I invited my boyfriend to come watch with me. When we got there we had about half an hour to kill before the show started. One thing you should know about me is I absolutely adore trivia and knowledge games, that is something that my family did and I grew up doing. One of my favorite topics is geography. We decided to play this geoguessr, touch the country it gives you on the map. It was set in Europe. The first few rounds went fine, they were more “obscure” countries that I wouldn’t expect an American who doesn’t like geography to know.

Things went bad when he was told to click on Iceland and pointed to the United Kingdom and said is it that one. He had this kinda half smile on his face so I thought he was kidding and said “you’re kidding right”, like he was messing with me and being silly. He got really offended and said I was being mean and insulting his intelligence. I, of course, apologized and said I didn’t mean to insult his intelligence I just genuinely thought he was joking. I understand if I was making fun of him, but I wasn’t. However I am honestly a little surprised he didn’t know something as basic as the UK. I’m American too and grew up in the same state so our schooling was very similar. It’s not like it was a random country in Africa (which I feel is less general knowledge than Europe in the US), it was Iceland. I feel like it’s reasonable to think he was kidding. We moved on but now I’m wondering if I was the asshole?

Edit: Thank you for all the responses guys! You’re right, everyone is smart in different ways (he would absolutely destroy me in sports trivia) and I should have been a little more conscious of my response even though it was a misunderstanding. I’m happy he even suggested playing that game with me.