Denmark likes to point out obvious things, especially when he knows it’ll embarrass the other person. Because yeah he’s a tease like that and it’s so damn amusing to him.
Like when he and Netherlands are making out—
Denmark: You’re blushing~
Netherlands: …No, I’m not.
Denmark: Yeah you are!
Netherlands: Am not.
Denmark: You are, and your face is growing even redder. Does kissing me make you nervous? Are you embarrassed? Damn that’s just too cute. You’re too cute, y’know?
Denmark: …Okay I’ll shut up.
and then they just go back to kissing.