However, there is only so many insults the actor can take judging by his response to Speidi's angry rants about him in scenes set to air on the Channel 5 show tonight.
The 68-year-old hints that something is boiling under his cool exterior following Spencer's epic rant, in which he branded him "a piece of s**t".
In a teaser from the latest instalment, James C is heard commented: "The only thing that I'd say, in all seriousness, that this might be a game but I take everything personally."
The Games Of Thrones star then chillingly added: "It could end up being nasty."
Celebrity Big Brother 2017: James Cosmo speaks out about Speidi's attack tonight
Celebrity Big Brother 2017: James Cosmo shocked Speidi with an eternal nomination
Celebrity Big Brother 2017 highlights
Tue, January 17, 2017
Celebrity Big Brother 2017: The best bits from the latest series including all the arguments, kisses and Tony the Pony.
1 of 14
Celebrity Big Brother viewers were surprised to hear Kim Woodburn urging Chloe Ferry to become an escort
This might be a game but I take everything personally!
Get Quotes on Home Insurance
The issue seemingly returns to conversation after Coleen Nolan tells James C that she wishes he had "told them off" just for her pleasure.
He then explains that it would be pointless to get annoyed as Heidi, 30, and Spencer are simply playing a game.
But, James C then jokes that on the outside he would maybe do something more than would be normal: "Like bite your f**king nose off."
Celebrity Big Brother 2017: James Cosmo won eternal immunity
Celebrity Big Brother 2017: Speidi slammed the actor last night
He went on to say that away from the programme, Spencer, 33, would be too "frightened" to act the way he has acted.
Meanwhile, during the episode, out will be revealed who will face eviction tomorrow. Eight stars are up, including Nicola McLean.
Celebrity Big Brother continues tonight at 9pm on Channel 5.