[Makes a surprised noise - but hair ruffles are still preferred to getting his butt pinched by your aggressive twin -
and he was only trying to be friendly! With a little bit of business on the side.]

Huh? [tries to smooth his hair back]
Oh, that good advice is for free, of course, only others might cost a little.

[Actually if you go by taxes on beer, buying from him is still cheaper...
but he'll surely get enough money from the regular alcohol and petrol tourists again.]