Q: Is it grammatically sound to use the word “disrespect” as a verb, as in “You are disrespecting me” or “Please don’t disrespect your father”? By extension, is the verb “dis” accepted now?
A: The Oxford English Dictionary is full of surprises. “Disrespect” has been used as a verb since the early 17th century. The OED, whose first citation is from 1614, defines the verb “disrespect” this way: “The reverse of to respect; to have or show no respect, regard, or reverence for; to treat with irreverence.”
By extension, as you say, the short form “dis” makes a lot of sense. The American Heritage Dictionary of the English Language now recognizes “dis” as an “informal” verb meaning “to show disrespect to” someone.