I don't think so? I've never seen him saying that
There's something called expressions that show more feelings than words
Sure they don't like it, both Asahi and Ikuo, but its exactly the point why they are being teased, they are cute whenever they react. But even if they don't like it, it doesn't mean they are offended and threatened. That's what friendship is, they know which buttons to press and not to press. Naru can flirt with Masato because he knows that's not what will hurt Asahi. Rather the word defective strikes Asahi where it actually hurts and immediately called Asahi out because he knew Asahi got triggered with the word.
I know you arent talking to me but ill just make something clear about my comments.
I think it's alright to do what they are doing. As long as everyone is happy and comfortable with it, everything is fine really.
It's just that i find it weird that they are actually ok and comfortable with it. Like in another manga, the uke actually lets his bestfriend french kiss him. (He was surprised about the tongue but he was just like "omg why you put the tongue??" And continued his day as if everything was normal and they even did other stuff that was intimate but both of them only saw each other as friends).
Sometimes author brings "weird" behavior like that and it 's bothering me. Naru actually kissed Masato and it was really no big deal for any of them. Once again, it's not bad as in if they are all okay about it, good for them, but i find it weird and irritatimg as a reader.
The way Masato flirts(idk if flirts fits here but whatever) with iku and the way Naru flirts with Masato is just so weird.
I know they arent serious and they are all friends but...thats just not how you should behave when you or your friend are dating someone already.
And it doesn't feel like a joke when they are acting like it's normal. (If it was done only to have a good laugh it wouldn't be the same)
It's not a big deal but it still feels weird and a bit annoying.