That he doesn’t lie
When you’re first getting to know someone, perhaps there will be things he isn’t ready to tell you. That’s okay. You need to earn deeply personal information about others, just as they must earn it from you. So, if you ask a date about something and he says, “That story is for another time,” or “Is it okay if we don’t talk about that?” so be it. That is at least honest. If, however, a date makes up a story or an answer because the truth is perhaps embarrassing or incriminating, that’s not okay. It’s fine to simply ask that whatever comes out of your date’s mouth is the truth, and if he isn’t ready to talk about something, he can say that, too.