The Master grins, catching Andrew and hugging him tightly back. He only pulls back a little so he can give him a proper hello kiss.

He doesn't find it particularly difficult to fake pleasantness like this to Andrew. After all, even back in the body this personality comes from, he had quite an attachment to this version (sort of) of the Doctor. And he still has all the James memories, so the fondness for Andrew is still quite definitely there.