We all know we're not supposed to text and drive. But what about texting with someone else when that person is texting and driving?

A tragic case being heard in a New Jersey courtroom on Friday is testing the limits of such responsibility in a potentially precedent-setting case. It's also serving as a cautionary tale about the sometimes irresistible lure of our mobile devices.

Here's what happened, according to local coverage of the high-profile case in the New Jersey Star-Ledger and the Daily Record:

David and Linda Kubert were out on theirHarley-Davidsonon Sept. 21, 2009, enjoying a winding Morris County road. That's when they saw, Kyle Best, 19, driving a pickup truck headed in their direction. In the final seconds before impact, the couple could see he had his elbows -- not his hands -- on the steering wheel, and his face was peering down.

Authorities would later determine that Best was using his cellphone to text with his girlfriend, Shannon Colonna. Best pleaded guilty earlier this year to three traffic citations and was ordered to pay $775 and speak at 14 schools about the dangers of texting and driving. His driver's license was not suspended.

That's a slap on the wrist, as far as the Kuberts are concerned.

The Kuberts, both 56, each lost their left legs in the crash. They have endured multiple surgeries and medical costs. They have also become crusaders working with state legislators to beef up punishment for drivers who text from behind the wheel.

But it's their legal action that is raising eyebrows: They are suing both Best and Colonna. The attorney for the Kuberts, Stephen Weinstein, says that Colonna -- who was also 19 at the time -- aided and abetted Best’s negligence by texting him when she knew or should have known he was driving.

No surprise, but Colonna’s lawyer, Joseph McGlone, disagrees. "It’s not fair. It’s not reasonable. Shannon Colonna has no way to control when Kyle Best is going to read that message," McGlone told the Daily Record.

McGlone has asked Morris County Superior Court Judge David Rand to dismiss Colonna from the case. Rand has indicated he will issue his decision on Friday in the case with implications far beyond his courtroom.