When he glances at your lips, it might signify one of two things: you have awful lipstick or something is on your teeth that is distracting him. We sometimes glance at people's lips to get them to stop talking. Kissing is the greatest technique to determine how the mouth appears. He will also slant his head to one side. This is called "reading lips". The opposite action would be if he moves his head to the other side. This is called "ignoring lips".