Who did she even cheat on her for in the first place? Keine?
This is just illustrating memes. It doesn't really have any kind of logical continuity. (See the PPX stuff where she was loving him then breaking him in half the next panel.)
Silly girl, we can always start over!
Note the green hat on Mokou: In Chinese slang, "wearing a green hat" means one was cheated by his/her lover (although usually used for men).
This one is referring to this situation: A man was cheated by his girlfriend, but when the cheating girlfriend offers to return to his side, he wholeheartedly forgives her and tells her that they can always start over.
As you would've imagined, this is mostly used as a form of mockery. Making fun of the utter bitch behavior of the girl by stressing that her cheated boyfriend "always has the option of forgiving", so she could, what else, cheat again.