His accusations are not false, I'm lying to his face. So.
Breaking him would involve telling him something that would hurt him in his most emotionally vulnerable spot, in a huge and horrifying variety of ways.
And I'm not being that honorable person, but I'm trying to mitigate my own evil somewhat by not being a TOTAL fucking piece of shit about it. I've already screwed up the honor thing, TBH, but I want to do this without hurting my friend. Former friend, I should say. I actually stopped thinking of him as a friend a long time ago, which makes me feel like a fucking bastard for saying.
...yeah, I did word my post in quite a dense way. Ugh. I think scrdest got it pretty right.
Anyways, I think you should talk to him and if he really is your friend, he should accept your reasoning. Friend accusing his own friend of getting along with a mutual friend is just silly. But since you are lying to his face, as you said yourself, this does complicate things a tiny bit.
Then again, you are saying you don't think of him as a friend anymore? Then you two really need to come clean on this thing. Of course I do not know how it came to this situation, but the vibe I'm getting is there are some underlying conflicts you two need to solve. A good, honest talk face to face. Try to keep it civil and solve this thing once and for all.
As for not being horrible person - the only advice in this situation I can give you is when you two are doing the talk, try not to throw in his face things like "yeah I lied to you back then but I didn't consider you a friend for a long time so it was ok for me to do that!" This is exactly something a horrible apologist would do.
Although how you get Team Fortress from TFC is a mystery. If I'd missed out the C or put 2 in by accident, I'd understand.
Well, I too was thinking Team Fortress so my brain qickly made decission that C must surely stand for "Classic". ˘\(°_o)/ˇ