My girlfriend is so cringe and I'm going to let her know.
What is it about her that makes you cringe?
It's just her style. It's really yikes and cringey.
Not liking her style is fine but it's her style not yours. You're likely going to hurt her feelings if you call her cringe so instead why not take her out and suggest some new clothes that you think might look good on her. She'll probably be very thankful for it.
Nah, I'm going to hurt her publicly. She knows I hate her style.
I think that it is just going to hurt her feelings. I think that it is mean to call someone cringey.