"Of course he's coming with us! He is our boyfriend! He has to agree to our choices!"
"Wait... What?" Mickey was shocked. Even if the stone magically made him the boyfriend of BOTH of the girls that sill didn't explain why they wanted to go bra shopping with him. "I wish I knew what my previous wish did."
And suddenly he knew. Apparently the reality have shifted so that any girls, once entered a relationship, form a strong dependence on their partner, to the degree that they even need their permission if they feel like buying something. And then the wish made both of the girls his girlfirends.
Well, that turned out much, much better than Mickey ever expected.