Stay and go along with her plan

There is really only one option and that is to stay, even if you wanted to leave it seems like your sister is so mad that she wont even give you a chance to grab your car keys or wallet and without those you can't go anywhere. "Fine i'll go along with your plan, I really am sorry" you say in an attempt to calm her down if even only a little, hopefully you can just go along with whatever she says for a week or two until she calms down enough for you to explain things. "So what is this plan then?" you ask, she smirks and says "good attitude but you can relax, after all this plan is all about giving you what you want". Now your even more scared, you still have no idea what she could mean but that look in her eyes tells you its bad "What do you mean what I want?" you ask timidly. "Well since you are obsessed with panties i'm going to let you wear them all summer, just not mine, i'll let you keep that pair since I don't want them back anymore but I was just heading out to go shopping so now you can join me to get all your new underwear for the summer". Your mouth drops open in shock as you stammer out "but I don't want to wear panties I didn't even want these ones it was just a mistake" but your please fall on deaf ears. "No excuses I know exactly what you really want so i'm just helping you, now put those panties on and get ready we leave in 20 minutes" and with that she leaves you in your room to get ready swiping your keys, wallet and even your phone from your desk on her way out.

For the next few minutes you go from staring at the panties to nervously pacing around your room wondering what to do, you could keep going along with her plan like you decided before and hope she changes her mind after a week or do you try to put up some resistance and argue back. Maybe you could just get ready to shop with her and not wear the panties, maybe she wouldn't check, then you would only be embarrassed from buying the new panties and you could just keep wearing your old underwear without her knowing. The chance to leave has already gone now that she has your keys and wallet so that doesn't seem like a good idea, but do you really have to go around wearing panties for who knows how long. You look at the clock and see you only have 10 minutes left to decided.