★ Be a baby.

[BettyBoop]

Okay, not sure if this will make sense but here goes:

This dare means you can only act like the age you are while wearing some form of "baby" clothing. You can do this for a day, a week, however long or short you wish.

For example, if wearing something like a diaper, sucking a dummy or wearing a onesie, you can behave normally around friends, family and whoever else.

Though if you are not wearing anything related to a baby you have to behave like a baby.
For example, talking in a baby voice, crawling, drinking from a sippy cup, asking people to take you to the toilet and whatever else you can think of that relates to babies.

Obviously, don't try to interact with strangers, you'll probably just scare them.