Dictionary/Vocabulary/所為
しょい · also そい
act; deed; one's doing; cause
巫山戯ないで。この出会いは偶然でも何でもない。疑った所為で君は俺の足跡をずっと密かに辿っていただろう。
Stop joking around! We haven't just met here by mere coincidence. You've been following me in secret all this time because you suspected me.