Taking cash from your mom’s purse “just this once” is how the second time starts.

Promising yourself it will not happen again is part of what makes the first time possible. What actually happens is that the first time removes the hardest barrier, the one made of never having done it, and the next occasion asks much less of you. After that it stops feeling like a decision at all.

If you need money, ask for it, even when the answer will probably be no and the asking is uncomfortable. Being short of cash is a situation. Taking it quietly is a change in who you are, and the two are worth keeping separate.