Translation problem....

Could anyone help me?

もうこれきりにしてくんねぇか
mou kore kiri ni shite kun nee ka

How to translate this sentence?

In my book, it was translated as " Could I ask for a favor this once?"

But I think it's not quite right......

Anyway, until I could translate this sentence, I'm stuck.....

And so...

I'll release a part of this chapter first.

Kaze Hikaru v23 c113 (removed)