IS IT OK TO COHABITATE?

IS IT OK TO COHABITATE? A friend of ours remarked that his mother believes that it is wrong to use the word “cohabitate”, that the proper word is “cohabit” and that “cohabitate” is a modern corruption of a good word. I remember that my high school Latin teacher, Lois Larson (the best teacher I ever had), introduced us to the term “frequentative” and used it to apply to the word “commentate.” She pointed out that some people objected to “commentate” as pretentious, but that Romans had formed verbs in that way all the time to show that an action was strong or repeated. I looked up frequentative in Wikipedia http://en.wikipedia.org/wiki/Frequentative and found examples such as “dribble” from “drip” or “scribble” from “scribe” in English and “dictare” (“dictate”) from “dicere” (“speak”) in Latin. And how about “waddle” from “wade”? So it’s OK to cohabitate because that’s how language develops.