to be on the up and up 开诚布公

英文释义
To be honest, worthy of trust, and free of any concealed or deceitful intentions.

例句
The unfriendly sales representative I spoke with yesterday seemed hurried and distracted, so I'm not so sure he was on the up and up.

这位昨天与我交谈的不友好的销售代表看上去慌慌张张，注意力不集中，所以我不太肯定他是否在讲实话。