I have been frequently told 笨蛋 by my friend when we chat in WeChat. The meaning of 笨蛋 is
However, while we are friends, I wonder whether she uses the term to swear at me or otherwise she is angry with me. Well, sometimes she didn't respond to me after saying the word. It is not to the degree that our relationship gets broken though, as we can continue the conversation in another day.
Is the word 笨蛋 used in such situations or can it be used in more casual situation as well to make fun of the other person? What kind of nuances does it have?