Besmirch

[Sarah]

To smirch or soil; to discolor; to obscure. Hence: To dishonor;to sully. Shak.

[Sarah]

1. to soil; tarnish; discolor.
2. to detract from the honor or luster of: to besmirch someone's good name

[Sarah]

To sneak up behind someone, then proceed to jump up and grab the victims head in one or both hands and then using momentum push the victims head into their own crotch. Popularized in the early 2000's in Southern California.