This dream could be a literal image referring to a rock & roll band. Whitesnake is a very successful hard rock / heavy metal band that was formed in the late 1970s and continues to record today. (see link, below.) One of their most popular songs was "Here I Go Again," a very dance-able song. So this dream might be the mind's way of saying, "here I go again."
Nothing
The snake is representing someone that you know in the real world.
From my own understanding, snake means someone doesnt like you.
See a psychologist.
the term is called deriucophemia
Dancing the Dream was created in 1992.
The ISBN of Dancing the Dream is 9780385422772.
Dream Dancing was created in 1941.
In this particular dream, the snake probably is a symbol for something untrustworthy or repulsive. Seeing the ex-boyfriend with the snake, it suggests that those feelings are associated with him as well.
Dancing the Dream has 148 pages.
A snake in dream represents a person who lives in a valley. A snake in a dream also means enmity from one’s in-laws or children, or it could represent the evil and jealousy of one’s neighbor. A sleeping snake in a dream means a sleeping enemy. As for an unjust person, a water snake in a dream means receiving help, or it could represent a verdict. Owning a snake in a dream means gaining power and authority. Its flesh represents enemy money, or it could mean joy. If one sees himself wearing the skin of a snake in a dream, it means that he will unmask his enmity toward others. Killing a snake in a dream and staining one’s hands with its blood means destroying one’s enemy. A snake in one’s dream also represents a rich enemy, for its poison means money. If one sees snakes being killed in the streets in a dream, it means a war. source: islamicdreamguide . com
If that is what you have dreamed, don't worry about it. I can assure you, DON'T WORRY! nothing should happen.