There are few things that surprise me anymore. In 20 years, I have sat through dozens of murder trials – each with a unique set of characters and stories to go along with them. But today was the first day I heard about a jailhouse love affair that started in a sink drain.

Apparently, two teenage co-defendants – who barely knew each other – in the November 2008 murder of Apex High School student Matthew Silliman formed a relationship while talking through the sink drain at the Wake County jail.

To be clear, men and women are housed on different floors at the jail, but somehow they have figured out how to communicate between floors by talking through the pipes connecting the sinks.

It brings to mind children creating an old-fashioned walkie talkie with two cups and a string. The difference: these "children" are charged with murder.

Drew Shaw says he and Allegra Dahlquist never spoke about the case per se. Instead, Shaw says they talked about religion, how she was a Pagan and he was a Christian who has recently become a Muslim. They also talked about what they had been reading and snacking on – Mountain Dew and Snicker's bars, for example .

The drain-pipe romance soon led to letters. Shaw insists he is not lying or trying to protect his new girlfriend in any way, but by the bright look on the young man's face when he speaks of Dahlquist, one can tell that his feelings are real.

Shaw was recently moved to another floor where he can no longer communicate with his love interest through the drain anymore. Word has it in the jail that the relationship is over. Shaw says she even wrote him an angry letter accusing him of ignoring her.

"The way she perceives things is that I've left her," Shaw said on the stand.

What do you expect when love starts in a sink drain? It has nowhere to go but downhill from there.