Why does that make it worse? Did she want to see the syph dick?

What you seem to not understand is that the buttplug is concealed. Your post is publicly accessible. Masterbating in public and having an item concealed in an intimate place while in public is completely different. If op didn't walk through a metal detector no-one would've known. So masterbating in public isn't ok obviously, but a buttplug (you can find it strange but that's about it) is not the same thing. Would you consider a clitpiercing masterbation? Is a Prince Albert masterbation? Is smuggling cocaine in your ass masterbation? Is exposing yourself publicly ok as long as your not stimulating yourself? Is lighting your farts in fire for a funny video with your mates masturbation or just banter? Where do you draw the line, exactly? As long as no-one can see it and no-one is harmed by it, it should be ok right?

Just admit your mistake and ask for a new check. Shit happens and it's not even that embarrassing.