[A ghost is pretty much what he felt like all yesterday (rather ironic - unsettling - considering how his two lovers thought he actually was dead) but Spike's reaction to seeing him does a lot towards setting that right. He even chuckles when Ianto shoves Spike into his arms, and he closes those arms warmly around Spike's stiff, shocked body.]
I'm fine. [Smiling at Ianto over Spike's shoulder.] I'm so sorry you both had to go through all that yesterday. I was there - right there, the whole time, but neither of you could see me.