Trying for baby #2...

Jes
Hey.. Like I said my fiancé and I are trying for baby number 2, but both of our families were not too supportive. Like, one day my fiancé made a joke about ne having a cub in the oven snd his brother say why have another when give already got one? 
My mom said she'll love him/her no matter what.
My fiance's parents feel the same way as his brother... That we don't need another child at this time..  
My fiancé says it's not up to them and to do what makes us happy..
I guess my question is, how would handle the situation and has something like this happened to you!?