Maybe you could get a tattoo sleeve (like one of those sleeves you can wear, I don't mean an actual tattoo, especially with fresh scars) and you can say you just think it looks cool if someone asks? Hope this helps☺️❤️
(Something like this?)
if you keep it wrapped in sports tape and say something about straining a muscle in your forearm (or you're keeping it compression wrapped to prevent swelling--a doc has had me do that with my ankle for months) I doubt anyone would question it. If tape, get it in a light color--black absorbs heat. 😉
temporary arm sleeves and (if you're comfortable drawing a little) good ol' sharpie + baby powder tats are options too. While temporary tattoos don't last as long as sharpie, taking a little care of it will go a long way.