although~; despite the fact that~
Expresses contradiction or criticism: 'despite the fact that...'
This pattern points out a contradiction between what someone is or does and what is expected. It carries a tone of criticism, surprise, or annoyance. For example, if someone is a student but never studies, you can say '学生のくせして、ぜんぜん勉強しない' to express your disapproval. It is not neutral; it implies that the person should know better or that their behavior is unreasonable.
You can use it with any statement that contrasts with reality. The clause after くせして often states the surprising or contradictory fact. The pattern is similar to のに, but くせして is stronger in its judgmental nuance. It is commonly used in spoken Japanese, especially in complaints or when expressing frustration. It is less suitable for polite or formal situations.