Yes, if you don’t like their partner have no moral fibre, or ability to stay the **** away from matters that need, let alone even desire your involvement.
FTFY
Why would you, apart from a sadistic desire to see your quest to invoke misery played out in front of your eyes? To think it’s doing your mate, or your ‘mates mate’ a favour is nothing short of delusional? I’m sure they are quite capable of making their own bad decisions without any help.