akuperma: You meant Kilaym (or Kilei B’heimah), not Shatnez.
Aryea: I cannot think of any possible issue with this. Maybe it’s somehow Chukas Akum? (That line was a joke.)
golfer: Even if you hold of no fish and dairy, lox and cream cheese should still be Muttar. Somehow the widespread Minhag on this (and on fish and meat) is clearly against all the Poskim, who clearly say the only issue is if they were cooked together.