Lying to them is simply pointless and that's why you always know where you stand with them!
Although because of this, because they openly say that, what they think, they consider egoistic, boastful and arrogant, this should be a sign VERY proud to his virtue. He simply cannot stand lies. It's pointless, stupid and a complete waste of his time.
When you actually accept them as people who don't lie, as people who always tell things the way they are, you'll get along with him perfectly, everything will become easier, and maybe it's his persistent truth that will change you for the better. You will also begin to walk the simplest path in life, which is the truth. We don't have rivers for nothing: "The truth hurts, but a lie hurts even more!"
What is this sign? That is ARIES!