BillieBob, I suggest you study the revised ANO which came out a few days ago - from which all JAR-FCL stuff has been removed.
The CAA was empowered to restrict activities sanctioned by JAR-FCL (e.g. to impose restrictive PPL VFR minima), whereas it has no such powers under EASA.
Read the Basic Regulation to establish the definitions for aerobatic flight - and the qualifications which apply to aerobatic instruction.
If you'd prefer, I can put you in touch with the CAA's Aviation Regulation Enforcement Branch and you can discuss it with them.
Blagger - I will log PIC, the other pilot may enter in his logbook anything he wishes but will not be able to claim the time towards the issue of a licence or rating. Since there is (as yet) no aerobatic rating, this is not great issue.
So does the 'pilot' (actually a passenger in the circumstances described) pay for your activity? Sounds pretty close to illegal public transport to me.....