He could tell she was trying not to laugh and he had to make the effort to not get so upset about it. Most of the time Marcus let his anger boil hot but he was breathing through the temper tantrums that wanted to surface. His expression was hard to hide though, his lips turning down into a scowl and his eyebrows furrowing.
Then she compliments him and the anger goes out the window and a small, almost shy smile perks at the corner of his lips. He rubs his chin thoughtfully and for a moment he isn't thinking about his son to be or Delaney. He's thinking he likes how Susan Bones isn't afraid and how she isn't throwing herself at him or hurling insults.
It's pure impulse what he does next and later he won't recall how he allowed it to slip so easily but it does. He blinks again and just as she tapped on his glasses he leans forward off the stool and reaches for her hand before she can pull it back completely.