this is how you repay me? 恩をあだで返すのか？

this is how you repay me? 反語とも疑問ともとれる言い方。0:24 I am the one who took you in, gave you a home, taught you, fed you, shared with you everything that I had. and this is how you repay me? 親に捨てられたお前を引き取ってここまで育ててやったのに、お前は恩を仇でかえすつもりなの？

Black Fairy: "There're So Many Ways To Hurt A Person" (Once Upon A Time S6E16)

1:32 you dim little shit. I hired you out of pity and this is you repay me. この野郎、情けで拾ってやったのに、飼い主の手を噛みやがって。

White House Down- You're a traitor sir

1:53 I gave you everything. this is how you repay me? あんたに全てを捧げたのに、こんなひどい仕打ちをするの？

Watchmen - Leave Me Alone