conjunction
Conjunction used to introduce a statement that contrasts with what one would expect from the preceding context. Often carries a tone of mild criticism or surprise.
彼は何でも知っていると言う。そのくせ、簡単な質問にも答えられない。
He says he knows everything. And yet, he can't even answer a simple question.
彼女はダイエット中だと言う。そのくせ、毎日ケーキを食べている。
She says she's on a diet. Even so, she eats cake every day.