Chances are he was looking forward to spending time with you, but spaced a band rehearsal. He means well. Try not to place tons of importance on timeliness. Assuming his latest love song is about you is a bad idea. Most likely, unless you fell for a bubblegum pop star, he'll play the angry singer and won't write a song about you until you break his heart or he breaks yours.
Album credits are for kissing peoples' butts or making amends.
Don't expect to be thanked in the liner notes unless you paid rent for the entire band for a year. His guitar is his child. Do not borrow it, touch it, trip over it or mock it. Even if it's a purple glitter guitar with a torn Alf sticker on it. His guitar is sacred.