hanky-panky
noun [ U ] old-fashioned informal uk/ˌhæŋ.kɪˈpæŋ.ki/ us/ˌhæŋ.kɪˈpæŋ.ki/
（尤指涉及性或金钱时的）不诚实的行为，花招
unacceptable or dishonest behaviour, especially involving sexual activity or money
There was a bit of hanky-panky going on at the Christmas party. 圣诞晚会上发生了一些不太光彩的事。