Was just playing at local club. Pot emerges where we're on turn and I have Ks8s on 965Tss after a raise preflop and the flop being checked through 3 handed. On turn I lead £25, next guy calls and preflop raiser makes it £125 with about £60 left. Me and the other guy have about £400 and there is prob £270 in the pot including the turn money. I tank fold at which point turn caller says 'if I call, will we make it friendly?' Preflop raiser says yes, river comes, caller checks saying 'I havn't even looked' other guy thinks and says 'we had an agreement' and checks back.

Surely this is clear collusion?

I was annoyed about it and got up shortly after