http://today.msnbc.msn.com/id/38206782/ns/today-entertainment/ MARQUETTE, Mich. — An attorney for actor John Stamos denies the "Full House" and "ER" star had a romantic fling with a 17-year-old girl who six years later is accused of scheming to bilk him of hundreds of thousands of dollars by threatening to sell compromising photos to the tabloids. A defense lawyer made the allegation Monday during opening arguments in U.S. District Court as Allison Coss and Scott Sippola went on trial, charged with conspiracy to commit extortion