You’re not the asshole — just a little bit savage.
Holly has been taking advantage of you for a while. You gave her the benefit of the doubt, even offered help if she was struggling financially, and she still kept “forgetting” her wallet and pushing shared bills after ordering half the menu. Then she invited you to an expensive restaurant, ignored your boundary about splitting the check, and smirked when you called her out — that’s manipulative, not forgetful.
Was ordering two extra entrees a petty move? Absolutely. But it was also the only way to make her feel the sting of her own game. You didn’t yell, cause a scene, or refuse to pay — you just stopped letting her freeload off you. She’s mad because for once, her trick backfired.
So no, you’re not the AH. You just taught Holly that “splitting the bill” works both ways.
