Transcript for Man sues NFL player for allegedly seducing his wife

We're back now with that lawsuit accusing an NFL player of seducing someone else's wife. The scorn husband suing Philadelphia eagles star Fletcher cox for alienation of affection and thousands of dollars, $50,000. ABC's Ryan Smith is here with that. Good morning, Ryan. Reporter: Joshua Jeffords claims his happy marriage was ended by an affair between NFL star Fletcher cox and his wife and now he's using an obscure law on the books in only a handful of states to strike back. He's known for being an unstoppable force on the football field. By Fletcher cox. Reporter: And the defensive leader of one of the NFL's best teams. Fletcher cox comes in to get the sack. Reporter: But this morning, Philadelphia eagles defensive tackle Fletcher cox sacked with a lawsuit for allegedly seducing another man's wife. Basically ruined my life because I thought I was going to be with this woman forever. Reporter: According to these documents filed in north Carolina, the two-time pro bowler being sued for alienation of affection. 34-year-old Joshua Jeffords, a former sergeant in the Marines, claiming his marriage to wife Catherine was destroyed after she met cox on a business trip in March. Our marriage was excellent from the moment I first saw her, I knew I was going to marry her. I thought definitely she was my soul mate. Reporter: The lawsuit alleging an adulterous affair ensued and the two stayed in touch via Snapchat and text. Cox allegedly texting her I want to get you pregnant. Catherine responding, we'd make some damn beautiful babies. I found some pictures that he had sent to her that I found highly inappropriate. I know that she texted him after I found out and the only thing she texted was he knows. Reporter: North Carolina is only one of seven states that allows so-called alienation of affection lawsuits. In 2010, a North Carolina woman won a $9 million judgment against the alleged mistress of her husband of 33 years. As for the Jeffords, Joshua says they split shortly after he confronted his wife over the alleged relationship. Joshua says he was admitted to a treatment facility for substantially emotional distress and is seeking at least $50,000 in damages. He's taken about everything from me that anyone could have taken that was important to me. Reporter: Cox who signed a six-year $102 million contract last year has yet to respond to the lawsuit. Josh's estranged wife Catherine did not respond to our request for comment and the pair are separated. Alienation of affection, only available in, what, seven states. Only in a handful of states and you have to prove there was love in the marriage, that the marriage was broken and the defendant in some way caused that. How do you prove that. Divorce proceedings. An affair is part of that. But then there are things he can use to defend that. He can say, for example, I didn't know they were married. Things like that but you're talking about $9 million in one case. $1.4 million in another case in 2001. A million in another. Why wouldn't he sue for more? There's been a movement to reduce the penalties from it and that might have happened here or he might just simply trying to say this is my costs. This is what I feel I suffered and that's what I'll try to get and on the books in a couple of different states. Wow. Who knew. In seven of them. A lot of eyeballs opened up in

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