Ted smiles warmly, and mouths "Love you," back. Even if he very recently napped, he too is getting very sleepy. On the plus side, if he gets a decent nap in now, he'll be able to more easily stay awake when Sherlock wants to sleep.

Eventually he assumes they'll feel safe enough in not constantly monitoring Joan's sleep, but he'll let them decide that, since he has no idea when it would be safe.