Edge: It sure isn't griffithii, but it might be usteriana, which is also bullated somewhat, and has exactly that red color underneath. Usteriana takes a long time to get really big, but when it does it is more than twice the size of affinis. It gets as big as C. aponogetifolia. Your plants don't look exactly like usteriana, however. They seem even more bullated and the leaves look a little wider.
Smaller C. usteriana
Bigger, but not full sized, C. usteriana