I just can't do it

Ella is getting big.  Too big.  She's too old now.  I don't want her to get any bigger.  It kinda hurts me to realize how big she is. She will be 7 months on Friday.  Michael and I have been bickering for over 2 weeks now about something.  And that something is a car seat.  He wants to put her new car seat in my car and I do not want her in it!  We are looking at this from two different views.. Michael is excited about her getting big, therefore a new car seat is welcome.  I on the other hand am excited about her getting big but a new car seat makes it real!  Dang car seats keep getting to me! So we have this car seat sitting at the top of our stairs.. for 2 weeks now.. and I just can't put it in the car.  I think I won't have a choice soon though because Michael doesn't want it at the top of the stairs anymore.  Anyone else have this issue?