かわくね

Hey everyone, this is a conjugation I’ve been catching a lot lately, instead of くない it sounds like くね. The best example is in Ranma 1/2 , where Ranma will say that Akane isn’t cute, but I’ve heard it elsewhere as well. Is this a dialect, lazy pronunciation, or is it a unique conjugation?

I suspect the second. Lazy probably isn’t the right word, kind of like すみません and すいません, where it gets blended a bit.

Thanks for the help!