This zany spy spoof might constitute the frustratingly uneven Roberta Findlay's most successful stab at comedy, much funnier than contemporary convoluted capers such as DEAR PAM and SWEET, SWEET FREEDOM a/k/a HOT NURSES or her later laborious LIQUID A$$ETS. Quirky credits oddly omit director identification but the screenplay's attributed to "Harold Hindgrind", a familiar Findlay pseudonym, and she does a brief walk-on during one scene. By association, I'll assume that she's DoP "Curtis Cockalot" as well, considering she frequently photographed her own flicks, usually resorting to her old sexploitation alias "Anna Riva".While the plot quickly breaks down into a series of LAUGH-IN style sexual skits overflowing with Findlay's personal brand of full-blooded Yiddish humor, the premise goes something like this. Brilliant but deranged Dr. Charles Cherrypopper (a scenery-masticating Jamie Gillis) has developed a machine that will give earth's entire male population an instantaneous and everlasting hard-on ! Ensuing chaos will enable him to basically take over the world. Government sends special agent Penelope Juiceslit (Darby Lloyd Rains, proving yet again she was one of the industry's most sophisticated comediennes) to thwart the mad scientist's evil plans.Narrative careens from Cherrypopper's laboratory to outrageously posh eatery Château Scrotum for a lengthy, barely related but side-splittingly funny sequence positively packed with low brow laughs. Porno punchline comes courtesy of a spirited under the table threesome involving Rains, Day Jason (Jean Jennings' duplicitous "best friend" from Armand Weston's mesmerizing DEFIANCE) and hunky Alan Marlow (womanizing anti-hero of Findlay's terrific ANGEL positively packed with low brow laughs. Porno punchline comes courtesy of a spirited under the table threesome involving Rains, Day Jason (Jean Jennings' duplicitous "best friend" from Armand Weston's mesmerizing DEFIANCE) and hunky Alan Marlow (womanizing anti-hero of Findlay's terrific ANGEL # 9), underscored with an absolutely hilarious Steve Ziplow tune entitled "Take Your Nose Out of My Pantyhose", which sums up perfectly all that was special and unique about early '70s adult movies. Ziplow directed the cult sleeper BREAKER BEAUTIES with Vanessa Del Rio and Sharon Mitchell and also performs a couple of comic cameos as the Château's snooty Maitre d' and a hysterical co-pilot.Movie ties with Metzger's MISTY BEETHOVEN for funniest airplane routine. While an impromptu orgy breaks out among the passengers, including a guy in a gorilla suit (don't ask) who spooks Darby as she takes it doggy style from ever ready Eric Edwards, pilot Sam Suckatiddy (the late Marc Stevens) is temporarily distracted by frisky flight attendant Sandy Fox, an all but forgotten starlet who appeared in Carter Stevens' LICKITY SPLIT and Claude Goddard's TEENAGE STEPMOTHER. Of course, such irresponsible behavior leads to a botched emergency landing and a particularly memorable send-off for Fox.Contrary to other fornication farces, including several of Findlay's own, SLIP UP delivers on both sizzle and silliness with a carnal connoisseur's cult cast giving their all. Seasoned Erica Eaton may be best known for non-sex character parts in movies like the Amero Brothers' BLONDE AMBITION and Chuck Vincent's BON APPETIT, but her appearance as randy receptionist Miss Muff Puff provides a welcome reminder that she started out in the trenches, performing with great gusto, whether with an elaborate jerk-off contraption or hirsute John Buco, the ineffective police detective "hero" from Shaun Costello's depraved WATERPOWER. Sturdy strumpet Ginger Snaps appeared in Costello's riotous LOVE BUS as well as the notorious ANGELA, THE FIREWORKS WOMAN by "Abe Snake" who's either Wes Craven or Peter Locke. Here, she has a snappy scene with David Savage, the compulsive masturbator from the running joke in Metzger's PAMELA MANN. Both Lynn Ashley, who plays Cherrypopper's accommodating assistant Sissy Motormouth, and hapless black stud Steven Blackwell were one shots.