I don't tell my roommate everything I do, cause it's not any of her business, also I don't want to explain myself for forever. Some things she might not understand, she's cishet, she can't help it. Anyways, when I got 2 helix piercings a few years ago, I didn't tell her I was going to get them, and never got around to mentioning it to her.
SIX MONTHS LATER she's like "oh did you always have those?" So I decided to not tell her about any more body mods I'd ever get. I have since gotten 2 more helix piercings and a third set of earlobes, which she has not noticed. I have also been stretching the first and second earlobe piercings. And she has not noticed any of this. The plugs for my lobes are even Monokuma colored (black on the left, white on the right) and she didn't even notice that!
When I got my first tattoo (the Joestar star), it's on my shoulder, so it was covered most of the time. But it still took me wearing tank tops a few times before she asked "Have you always had that?" But this latest tattoo is bigger, and black (and I am VERY pale), and in a very conspicuous spot on my forearm. I have been wearing long-sleeve shirts to protect the bandage, but I just took it off in the shower. And I, a smart person, forgot to get a paper towel to dry it off.
So I have to go out to the kitchen, in my towel, with my arm held out/up so the tattoo won't accidentally touch anything icky. And she SEES ME and asks me what I'm doing. Getting a paper towel, I say, and then I start blotting my arm. You know, a very visible movement, onto the tattoo, which is very clearly on my skin. AND SHE DOESNT NOTICE.
So. We shall see if she actually notices tomorrow, when I'm wearing short sleeves to let it get air.