Clearly, you’re uncomfortable with the idea of a “free hug”, or you wouldn’t be asking about it. There is a powerful element of society who would force this “free hug” upon you, using nothing more than persuasion and good looks.
What, exactly, are they up to?
My theory is they’re trying to undermine basic primate behaviour. Hugs are an intimate form of communication that release either good chemicals or bad, depending on the huger and the huggee. Back on Planet Neecknaw, instead of hugs we have grooming — checking our close friends and family for fleas and other fur foibles. (Of course, we rarely find them now that we’ve relaxed our harsh Anti-Bathing Laws, instituted in the Stinky Ages.) Now, would I let a total stranger grope through my luxuriant back hair on the street? I think not. That would generate some bad chemicals — the kind that make Kang angry!
Perhaps these “free huggers” are trying to extend the warm blanket of close friends and family to everyone. If everyone becomes a friend, this would make warfare rather difficult to pursue. As a former interstellar warlord, I cannot condone this subversive movement.
The best solution: if you want the hug, I’d insert the crass note of commerce to it, and give them some money.