Permanent marks on your body are the worst decision ever.
When Scott told Stiles that he wanted a tattoo, all Stiles wanted to say was No, don't, please. You deserve better.
It's not worth it.
A simple whim on one day can lead to flannel shirts and jeans forever, even on the hottest days of summer.
Stiles knew this all too well, though he'd never tell Scott about that first night he got drunk and decided that his arm would be a cleaner surface to cut than his thigh.
That he'd been cutting on his thighs for years, where shorts could easily cover them, but that one whim sentenced him to covering up even in the hottest months.
And now he's hiding forever.
After that night, he'd figured what the fuck, why not? because he's stuck with scars that will never heal, will never not be immediately recognizable parallel lines lining his wrists. So why not make a few more?
Permanent marks are addictive like that.
Now shorts are out of the question too.
The ones with meaning are the worst, because you won't want that meaning forever but it stares at you each day. The failures that he'd cut representations of into himself will never leave his body. The crudely carved S on his wrist will always remind him that it's his fault that he dragged Scott into the woods that night. The D on his arm will stare back at him every time he undresses, reminding him of his pathetic need to be loved, but that no one will want him. Worst of all, the aged MOM on his thigh, one of the first things that he cut, reminds him that everyone he loves will someday be gone, and no matter how many times he's tried to cut over that, to erase it, it's always there.
So when Scott wanted a tattoo, all he could think was no, don't, because meanings change and there are some memories that you will want to erase. Because when you regret permanent marks, it doesn't make them go away.
Scott will probably make fun of him for years for having been unable to watch the needle pierce his friend's skin, over and over, but he couldn't watch without feeling the itch all over his own arms, imagining the feeling, imagining the release when Scott cringed at the pain, but he could only imagine the relief it would bring himself. He couldn't stand the guilt he felt.
That's the problem with permanent marks – the joy that they bring is ephemeral; the pain it brings is not.