to kill with kindness: (verb phrase) to be overly nice, to make another person uncomfortable with your hospitality

A: " I ate dinner at my girlfriends' parents' house last night."
B: "How was it?"
A: " Oh, it was awful. They killed me with kindness."
B: " What do you mean?"
A: "Her parents forced me to eat too much food and they insisted on helping me with everything. They wouldn't even let me go to the bathroom by myself."