They pay the bill

Once they finish their dinner John asks for the bill.

They pay the bill and all walk out of the restaurant.

Mary: "It's really such a nice night. I think it would be great if we could have a walk in the park."

John: "Yeah let's do that"

The girls cheerfully agree too.

They don't notice you actually walked behind them and were following them every step they take.

The girls bodies were really sticky and messy but they totally weren't aware of their current situation.

Some places of the park were pretty crowded and everybody that sees the family has a look at the yough girls walking around naked.