There could be possibilities of feeling insecured and being possessive, which is quite common when you are friendly or even for newly married couple.  It seems to me that you are also seeing your father in him (your friend).  You have so many fearful thoughts, for which you talk to your friend what you feel in most assertive manner and not aggressive way.  Try not to involve any third person in your discussion or relationship. Build a strong bonding and understanding now itself, before you take the decision of getting married. If required go for a pre-marital counselling; to understand both your expectations, values and more.