I've known several people who have consented to ignition at Happy Hour
I was referring to the specifics of the (?) Chivenor case which finished up as GBH and is in fact used in legal textbooks as an example.
P'raps it's only GBH (and above) you can't consent to; IIRC there was another case with some strange blokes who liked drilling holes (with a Black and Decker) in each others dangly bits (
)
Consent not a defence there either....