Thinking About Blowjobs Without Semen

I want to stress that this an obsessive thought, but nothing I've actually done. I've given blowjobs to lots of guys, and find it a real turn on, but learned that I don't like cum in my mouth at all. But most guys want that, so I find myself in a dilemma. My thoughts sometimes go to prepubescent boys who are too young to ejaculate. I've occasionally seen one peeing outside, and once I saw a boy with an erection but he soon got embarrassed and hid it. I know it would be wrong to do this, but I wonder what it would be like to just suck a boy who I knew could never cum in my mouth so it could go on and on and on.