It's kind of nice to see Sherlock relaxing as well. Though Ted's sure he's mentally still going over the Rupert case. Hopefully Joan isn't though.

He scoots a bit closer behind/next to her, draping an arm around Joan's waist and leaning gently against her. "I love being in the park," he says softly, looking around them. "Just... people enjoying their day, taking some time to relax or to play. Even if you're sad in the park, on a day like this, at least it's a better place to be sad than being stuck inside."