When you have a small penis, most of your sexual fantasies end up being about going down on a woman rather than fucking her. Because this is the only way you can imagine a woman actually feeling pleasure from you.
Of course in real life a woman would never be satisfied with just oral. For them, oral is just foreplay to warm them up before they get fucked by normal penises that can actually fill them up and reach their pleasure spots. They'd never have any reason to let a man with a small penis eat them out.
But when you have a small penis, like me, you're a virgin anyway. So you can imagine that they'd let you do it, just in your fantasies.