Yes, Sagittarius men occasionally lie. They may not be truthful with every detail of their life, but they will usually tell you the truth about important matters. If a Sagittarius man is lying to you, he likely has something he wants from you and isn't interested in being genuinely honest with you. He may use lies to manipulate or control you. If a Sagittarius man lies to you, it's important that you refuse to believe him and move on.