Frozen
Now I'm not going to make you go into a lingerie shop and ask one the workers to size them up but there are a few rules.
1) You may not go to the self checkout, I want you to have to someone at a checkout.
2) You must not just grab any pair of panties, if feminisation isn't your thing pick the pair you'd most like your girlfriend to wear, if it is your thing then pick the pair that when imagine yourself wearing them, makes your clit try the hardest to escape from its prison.
3) Make sure you get a suitable size, check online what your size in female undies is and leave room for your balls, yes this will you having to look through panties to find the right size and yes someone might see you. How humiliating.
4)You may mix them into a larger shop but you can not lie or make a reference to them being for someone else if you're given a funny look.
So do you want that precious ice cube? Remember if you don't do this task then the cube is lost forever and you cannot come back and complete the task later.