A routine shoplifting arrest at Walmart escalated into a tale of meth charges and "prohibited sexual conduct" between a brother and sister.

When Charlene Ellet, 25, was detained for alleged shoplifting at a Porter, Texas, Walmart, her brother Cameron Beck, 26, came looking for her at the loss prevention office. County deputies searched their car and found a burnt lightbulb and a cut pen, which tested positive for crystal meth.

The two admitted to smoking the meth about two weeks prior, and were booked for possession of a controlled substance (and a shoplifting charge for Ellet). And that's when things got really complicated.

Police placed Ellet and Beck in adjoining cells, and while they were filing the booking reports, the two began "kissing each other on the lips through the bars."

After double-checking that they heard that whole "brother and sister" thing correctly, deputies questioned Ellet separately. She admitted to a sexual relationship with her brother that started when he was released from jail in November—although she insisted they had different fathers.

She said the two had been living in a motel with her 2-year-old twin daughters, and they put up a partition or went into the bathroom so the babies wouldn't see them having sex.

Prohibited sexual conduct laws in Texas apply to half-siblings, so the two were charged and remain in jail. Ellet's daughters were released to her sister.

[H/T Fark, Photo Credit: Montgomery County Police Reporter]