Jon and Lucy Liu's son-BTS season 4

This is a continuation of the last story but is set about four months after.

Joan woke with sunlight coming through the window, it was beautiful. She looked over and saw Sherlock's half of the bed was empty. She put on her dressing gown and went downstairs.
'Sherlock?' No one answered, he must be out. She picked her bag up off the table and checked her phone, there was a text from him.
Sorry i'm not there, Gregson needed a hand with a case. Make it up to you tonight. Love you.
She smiled then went into the kitchen to get some coffee. She went and sat down then she got a call from her mum.
'Hey mum....

They both sat in Gregson's office as they questioned Oscar about the drug dealer, they hadn't said a word to each other since leaving the brownstone. Sherlock could tell when she was annoyed with him, he had seen that look many times. He moved closer to her and buried his face in her hair.
'Joan, please, talk to me.' He kissed her shoulder. 'I'm sorry.'
She sighed.
'I know you are, but you've been keeping more secrets from me first it was Irene, then your brother now this. How many more can i expect?'
'No more.'
'You sure about that.' He placed his forehead on her shoulder, not wanting to look in...