Allison Coss A woman by the name of Allison Coss is claiming a romantic encounter with Stamos in 2004 occurred when she wasnt yet legal. Coss was a high school student on a Spring Break trip to Florida at the young age of 17 when she had fling ... Prosecutors are asking a judge to bar questions about Stamos sex life and whether he had an intimate relationship with one of the defendants Allison Coss. They say its irrelevant. Coss and Scott Sippola are accused of demanding.