Am I tripping?

So I’m at my bf’s house and we’ve just picked up his sons from their mother. The boys are excitable as usual and they’re showing me toys and telling me about what they been up to this week etc. Anyway the topic of cheerleaders came up and one asked what’s a cheerleader and I was explaining. Then my bf just starts interrupting saying cheerleading isn’t for boys and I say well there are some boys that are cheerleaders and they’re like gymnists and he says “yeah, sissy boys. Don’t be telling my kids about that. They don’t need to know about that” in like an extremely rude way and starts yelling at me in front of them like I’m a child, And I’m like okay so I can’t speak and say what I want to? I’m not telling them anything wrong. I’ve been around these kids all their lives and now all of a sudden he’s gotta tell me what I can say and what I can’t? I really just feel like going home right now. He was really freaking nasty towards me and I really am no longer in the mood to even be around him.