I'm not much help. My 2.5 year old has curly hair, except the front! So his bangs are so straight. I'm just waiting for them to grow enough that they will rest on the side. I'll try to take a picture in the morning.
My mom got him ready for church on Sunday and I was impressed that it was staying on the side. I found out that night that she used a little hairspray. It did the job for a few hours though. Maybe try some different lightweight products?
Mom to a girl - 6, a boy - 4, and Baby - 2