For Bernard heart, i think you need to have at least 50-60 relationship with him. Then, just go hunt with him on Friday. When there's a choice whenever for you to sleep on the bed or the floor, choose the bed. Then in the morning, there will be another choice appears whenever you should stay close or away for him, choose stay close.
If i remember it correctly, the conversation at the end of the hunt should change and there will be a notice that Bernard loves you more.