The one that will be taking the lead will need oil or lubricant. They sell them here. If you need help finding the right one when you are ready then I can help you.

[He knows that will be embarrass his little brother but he wants the offer to be clear.]

From there he will pour some onto his fingers to coat them then bring that hand between the legs of his partner. There is a hole there which it is best to gently rub with oiled fingers before sliding one of the fingers within...