Green’s Dictionary of Slang

to enjoy for free the pleasures that are primarily made available to a celebrity or laid on at an important event but become equally available to anyone who cares to struggle hard enough to grab them; in general use, to define the taking of any benefits that one has not made due efforts to deserve.

1943		H.A. Smith Life in a Putty Knife Factory (1948) 105: I didn’t intend to do any free-loading on you.
1955		R. Graziano Somebody Up There Likes Me (1956) 223: Why, you bum [...] all of them times you come over to my and Lulu’s camp and freeload off us.
1963		M. Braly Shake Him Till He Rattles (1964) 108: How many times have I freeloaded on you?
1975		Sun. Times Mag. 12 Oct. 28: He gave up ‘real’ work to freelance and freeload.
1994		I. Welsh ‘A Smart Cunt’ in Acid House 254: We [...] freeloaded as much drink as possible.
2005		B. Hare Urban Grimshaw 203: I could have freeloaded drinks all day in Beeston.