There's nothing wrong with marrying a girl half your age.

Unless you're 27-year-old Robert Nickson Jr., whose wedding plans were ruined this week after Delaware County authorities had a chat with his 14-year-old fiancée.

Police say Nickson recently took the girl to the mall and bought her an engagement ring. They met about a month ago through a mutual friend.

The juvenile told investigators that she had sex with Nickson on at least four occasions at the Lower Chichester apartment where he lives with his father, according to the criminal complaint filed Wednesday.

Nickson has been charged with statutory sexual assault, aggravated indecent assault, corruption of minors and related offenses. He was taken to the George W. Hill Correctional Facility after failing to post bail.

Court documents state that Nickson and his intended bride knew what they were doing was illegal, but they "didn't think they would get caught."

How did they get caught? Facebook, of course.

Their profile pictures were photos of the two of them together. And they both posted updates stating that they are "in love" and "engaged," according to police.

Text messages indicate that Nickson and the girl were worried about nosey detectives breaking up their relationship.

According to the criminal complaint, Nickson texted her: "i wish i had my own place and you lived with me . . . i would get to see you everyday no matter what time i get done and no one would know where it is."

No one answered the door yesterday at Nickson's apartment. He's due in court next week for his preliminary hearing.