Snowball is when you cun in her mouth and she shares her prize with someone through a french kiss. The someone can be you or another lady.

Venus Butterfly is a hoax. Supposedly some oral technique that drives women crazy and to the ultimate orgasm. It became popular when mentioned on an old TV show, LA Law.

Snowballing is the act of cuming in your partners mouth. Then He/She gives it back to YOU!, not SOMEONE!, YOU!

If you come in a ladies mouth and she shares it with another lady that is called a snowball as well.