1. be clear and honest with someone
to be straight with you, I don't think you are capable of doing that
When you are 'straight' with someone, you are honest with them, often risking offending them through criticism. Sometimes people will ask you to be straight with them because people are often dishonest when they try to avoid upsetting people. Asking someone to be straight with you can often follow an argument if you think the person you're arguing with is holding something back. You might hear this used in both social or professional contexts, and you can easily replace 'straight' with 'honest'; as in, 'to be honest with you'.