he would be happy for you to have a few more boys until he got his girl 
sorry but they arent just some commodity that you can just pop out, they will be people in their own right that deserve and need love from their father as well, how will they feel when they are older and they know they were only born because you were 'trying for a girl'
i am the mother of 4 boys and then 1 girl, we went into preg no 5 knowing we were likely to have another boy (i have met two consultants recently that said it is more unusual to have the other sex when you have a number of one sex already) we would have been more than happy with another boy, infact despite 2 scans telling us no 5 was a girl we didnt believe it till she was born and we saw for ourselves!
my dp has always joked about how mad it is he is father of 4 boys and is not a blokey bloke and he assumed he would have a girl in that mix, he loves dd but no more than he loves the boys, and tbh at 16mths there is no difference she is just like her brothers were at that age. is it lovely having a girl? yes but just because i can buy different clothes, which would be the same had i had 4 girls and then a boy!
our primary concern each time was that the pregnancy and birth went smoothly and mum and baby were fine each time NOT the sex of the baby.
i have had lots of comments along the lines of 'oh you finally got a girl or you kept going till you got a girl' etc etc
they are hugely annoying we had a 5th baby because we wanted another CHILD, regardless of their sex, my boys are not second best to their sister and never will be and i resent the implication that they are, esp when it is said with them in earshot!!