All images are of the same specimen.
No interactions present.
This one is a puzzle. It looks very black-white-grey, like A. silvaticus and circumscriptus, and the white (not yellowish) foot fringe fits those. The flanks are abit dark for silvaticus, but the back is unspeckled with black, ruling out circumscriptus. The pale stripe above the dark one isn't typical of any species. Unless you have a photo from above and from underneath, I'd probably just say Arion sp.!
...no foot view, well unless you can make out what is going on in the last image on the right.
An iSpot Project- HELP WITH IDS - UK & Ireland Community - PLANTS
Lat/Lng: 53.2055, -0.5631
OS grid ref: SK960685
Backies woods, Boultham Moor, Lincoln.