Atheism and Baptism

My husband and I were married in the church and baptized our first two children. We did these things because we were raised to do so, and mostly out of tradition. We haven't been to church in years. I have felt no connection to the church or the faith in a very long time and I'm in my 30's. My husband has come over to the dark side over the last few years. 

In the past few years we have moved from agnostic right into athiesm and boy are we happy about it. We are raising open minded children right along with it. We are content with this decision. More than content really, we both are very happy and I personally feel like this was a long time in the making. 

Now I'm having my third child and I admit, I'm struggling with baptism. I do not want a baptism. I do not want to promise my child will be raised in a faith we don't believe in. However, each of my children has worn the same baptismal gown and has their name and date embroidered in the hem. It's a beautiful tradition. So now I'm struggling with this damn issue. I'm having difficulty letting go of the gown and party after and I want his pictures in it. Dumb huh?!? 

Any tips about how to move forward with this? Our families will try to push us towards baptism anyway, so they are useless to ask. I'm against it. 

These are my boys on their baptism days. The dress is made from scraps of my wedding gown (which was also made) so I'm just being a sentimental nut here.