This is mainly because online dating is not subject to geographical restrictions like traditional dating methods. In other words, you can search thousands of potential matches on dating sites, but any form of offline social gathering can't actually achieve the same effect. So is the bubble. Card bubble means knocking on the gun, also known as knocking on the bubble, which is a popular word on the Internet. It means that both men and women have sexual fantasies and do some hidden things by voice. In order to avoid disharmony, KP, card bubble, knocking gun and knocking bubble are represented.