Would a guy make things up in order to make a girl jealous?

Most of the time we would so we can feel better. Guys don't like being crushed, so in some cases, yes, we would lie not to make the girl feel bad, but for us to feel more dominant and more powerful. It's almost second nature to do that so he probably would care less about how she feels, because it's making him feel a lot better. Besides, he probably wasn't lying, just bending the truth. He might have been busy, but not that busy, and might have lost interest in her, but not seeing other women.