COULD Paris Hilton have avoided the embarrassment of having half the world see her having sex with ex-squeeze Rick Solomon? Spies say Paris knew the tapes were being shopped to Internet porn entrepreneur Roger Vadocz in July and had restraining orders drawn up, but “never pulled the trigger – no one knows why.” Perhaps because, even though Paris says the tapes are “humiliating,” she’s more famous than ever because of them. Meanwhile, the high-stepping Hiltie ignored her “two-week lockdown” familial restriction and stepped out Saturday night at Club Lingerie in Los Angeles for a rock concert – disguised in a long, brown wig. Paris is now back in New York, and looked “very angry” during the whole flight back from Los Angeles Tuesday afternoon because she “had to fly coach – United wouldn’t upgrade her,” our source said.