She knows how things work. Guys and girls cannot be friends unless neither has any attraction to the other, and even then, issues will crop up when your friend gets a bf or gf. It's best to not get too close with many members of the opposite sex as friends, unless you're gay, and just be friends with ppl of the same sex.

深淵を覗く時、深淵もまたこちらを覗いているのだ