The problem isn't the family tho, its him. Generally one makes it clear that one has a partner and an invitation is extended to both.
How is your relationship w/his daughter? This may be more about her comfort level (i.e. you not replacing 'mom' at a family gathering).
Have you met his family in another context? Maybe you should invite them over for dinner when his daughter is visiting mom. Be strategic (and sensitive) in how you insert yourself into his family.
Oh, and you should definitely tell him you are hurt that you were invited and then (basically) uninvited, or conditionally, however you want to phrase it. It was a mistake on your BFs part (not his family who possibly had no idea he has done this). Explain to him it makes you insecure about your relationship. Try not to yell at him when you do this.
Last edited by IndiReloaded; 17-06-11 at 02:22 AM.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh