Well, I'm pretty she just meant that since they can't help anyway, it's best if he doesn't explain the details of the problem. That way he doesn't need to talk about it and be uncomfortable and they don't need to keep worrying needlessly too.
On another note, Yeoryeong sure is bothering me with this "no flirting". The hell, she can flirt with whomever she wants. Even if she were a jealous gf, you can't just prohibit people from talk, sigh.