Who will baby look like ??

I'm mad that my fiancé says if we have a girl it will look like his sister... But nothing like me and I had the nerve to say oh really it's our baby not yours and hers you didn't have sex with her now!!😡😒. I'm so pissed off about it  I understand the genetics and stuff it's just I can't calm down when we argue about it 
Lol am I over exaggerating???  Ps I am a very very moody person and I blame my baby hormones idk but help?? Lol what do you think?  Only reason I get mad lol is he brings it up non stop 😐