It would be great to find a girl who could lick your dick all the way through. That's not how all girls are. It might be easier to find a four-leaf clover than a girl who is willing to let your cock go all the way around her mouth. The main reason a woman can't do that is that it makes her gag. The back of your throat contracts when something foreign touches the back of your throat, the roof of your mouth, the back of your tongue, or even the area around your tonsils. This keeps the foreign object from getting past those areas and giving you pain. And sure enough, a man's dick would hit all of those places if he tried to put it below her mouth. While the gag response is an important part of the body, it makes it hard for women to have a big hard cock going in and out of their mouth. People aren't born with this reaction, but as they get older, they probably will develop it. Some people don't get it at all, even when they're adults. You only need to find a girl who either doesn't have a gag response or is willing to get rid of it so she can swallow your dick whole.