Fish the swim , cast to the spot, catch the fish you want and then "soap" the spot when you're done 🤫 🤣.
I'm joking about the soaping obviously. I'd have had words if it was me and also told the bloke I'd see fish showing elsewhere before he turned up to see if I could get him to move. I'd find it very hard to move or not cast to a fish holding spot.
Regarding the soaping, I'd never heard of it until I got on dinton. There were a couple of anglers who I found out were right nasty towards other anglers. I got told by one of their good "friends" that they would often soap swims that were fished week in , week out by particular anglers. If the certain swims held fish because of a weed bed then they would "napalm " the swim (drop aquatic weed killer bombs) into the swims. When I look back there were certain anglers that would fish the same swims week in , week out and catch fish for it to suddenly die a death.