The legal battle between Robin Thicke and the Marvin Gaye estate over this summer's dance hit 'Blurred Lines' is about to get heated. The surviving Gaye family are mad as hell and they are not going to take it anymore.

The late singer's son, Marvin Gaye III, spoke with TMZ recently and he's not happy with Thicke's pre-emptive lawsuit in which he's asking a judge to block any impending litigation from the Marvin Gaye estate. The son also claims that Thicke has made a successful career for himself imitating his late father.

Gaye's son says that Thicke's lawsuit has caused distress among himself and his family. He contends that 'Blurred Lines' is clearly a rip-off of Gaye's classic song, 'Got to Give It Up.'

"If you listen to the music, I'm sure anyone will see the similarities between what my father does and what he tries to do," he says.

In Thicke's defense, the singer's lawsuit states that his song is an original composition and just because it "sounds similar" doesn't mean that infringement is actually involved.

Marvin Gaye III wouldn't confirm or deny that he will sue Thicke for copyright infringement. All he would say is that his counsel is taking care of business -- whatever that means.

The smile on the face of his wife, Wendy, seems to confirm that Thicke better get his attorneys ready -- it's about to go down!

We hope that both the Marvin Gaye estate and Robin Thicke can amicably work something out. Both songs are great and they mix really well at parties. We see no reason why both tunes can't co-exist.

Talk about blurred lines.