a relationship should be built upon trust and honesty.
due to this incident, your trust in your bf has been eroded and it
is eating at you. You will become suspicous of him in everything he
does.
I would advise that you ask your bf, but put it nicely and gently.
Don't use 'you', use 'I'
for example,
I noticed that sometimes you refer to me as your friend. I
am a bit uncomfortable when you say that.
if you explain to him your reasons why, I'm sure that he will
understand. If not, then he probably has something to hide.
I can understand that you are scared and afraid of damaging your
relationship, but is your relationship that fragile ???
if so, then is that relationship worth keeping ?