用情不专。你肯定是在找这个词。

A 2-timer. That must be the one you're looking for.

youdao

他是一个用情不专的人。

He is a fickle lover.

youdao

女工们则歌唱吸烟的快乐，以烟圈的飘忽不定来比喻男人的用情不专。

The women sing of the joys of smoking, comparing the fleeting smoke rings with the fleeting attentions of the men.

youdao

女工们则歌唱吸烟的快乐，以烟圈的飘忽不定来比喻男人的用情不专。

The women sing of the joys of smoking, comparing the fleeting smoke rings with the fleeting attentions of the men.

youdao