look up any word, like bukkake:
 
1.
The sperm left over on the womens body after the male ejaculates onto the her, then the female cleans it off and the residue left over is the sperm slug.
Little sally went down on big johnny and as he tells her to get off of him, he ejaculates onto her so she goes to the bathroom to clean off. As she gets ready for round two big johnny tells her " little sally you have sperm slugs all over"
by bmtbaseball31 September 10, 2009