told her I had to run to a friends house to pick up some band equipment and to download some songs we had to practice.
She asked what time you got home, too. Have you tried to be a bit more vague/mysterous of your activities? You don't lie, but be more..."general" so that it would make her wonder what's really going on. She needs to be interested in your life. Don't be so fast to give her a play by play.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!