Snowball kissing is a sexual act where a person receives semen in their mouth during oral sex and then passes it on to another persons mouth through kissing. It is also known as "cum swapping". The term "snowballing" usually implies the involvement of the original person who ejaculated into their partners mouth, while "cum swapping" is more general and could apply to people sharing a semen-saliva mixture that neither of them originally ejaculated. Snowball kissing is a risky sexual practice that can transmit sexually transmitted infections (STIs) and should only be done with consenting partners who have been tested and cleared of any STIs.