Britney filed for divorce yesterday behind K-Fed's back and is seeking sole custody of Sean P and Jayden. Brit then reunited with her old manager for a little fun ice skating outing to show off her smiles. Now TMZ reports that Kevin is thinking of challenging custody of the kids - it may be his only hope in cashing in on Britney's fortune. Brit has acted as the primary parent to Sean and Jayden while K-Fed is trying unsuccessfully to sell records, so it seems unlikely that the father of 4 has any hope in winning this battle. And we're also hearing that Brit may just be a bit smarter than people gave her credit for. Filing papers this week was perfectly timed to ensure Kevin got just a little less of her money. Here's more:

She filed two years and one month from the day of her marriage, on Oct. 6, 2004. Her prenup, according to legal theorists, evidently carried increases for Federline for every year of their marriage. And those deadlines, they say, likely had 30-day grace periods.

Hence, Nov. 6 would have been Britney's last chance to get out of paying a third year of alimony settlement to a basically talentless slacker who was a drain on her finances.

And in the end, money is probably what Spears’ divorce is all about. Since she deliberately showed off a new trim body on David Letterman’s show the other night, Spears is obviously getting ready to go back to work. If a new album and tour are on the boards, Spears obviously doesn't want to share the proceeds with Federline. It was clearly better to get out now, so that K-Fed can lay claim to only half of Spears’ earnings during what has been the most fallow period in her career.

We just can't get over how quickly Brit has bounced back! Clearly this is part of the comeback plan, but who cares! More pics of Brit so