「みろ、お前のお陰でフラれまくりだぞ」「そう？日頃の行いのせいじゃない？」

「、」「？？」

'Look, thanks to you I keep getting dumped.' 'Really? Isn't it because of your everyday behavior?'

Literal

''Look, you [possessive-の] thanks-to dump-[intensive-まくり] [emphatic-だぞ]'' ''Really? Everyday behavior [possessive-の] cause [is it not-じゃない]?''

A barbed peer exchange. フラれる is the passive of フル (the casual katakana-written 振る, 'to shake', slang 'to dump/reject romantically'). ~まくる/~まくり is a colloquial intensifier meaning 'to do X all over the place, excessively'. お陰で ('thanks to') is normally positive but is often used sarcastically for 'thanks to your crap'. 日頃の行い ('one's everyday conduct') is a moralizing phrase implying karma — your behavior has consequences.