FIL's comment on LO pic. **UPDATE pg 2

I need some guidance on what to do about my pil's.

Simple BG: my LO is 4 months, while I was still pregnant my mil started the jealous thing over my mom. My mom was the one that would be keeping lo while I worked during the day. Mil would say stuff like it's not fair her mom gets to keep him during the day, and her mom is going to get to see him more to my dh. My dh at first was on their side , and thought nothing was wrong with them untill lo was born. When lo was born things changed and he started seeing them. Pil came over the day we got out of the hospital to cook us dinner and 4 days later for dh's birthday. Those were both in June, the last time they came over was in August to show us their brand new car. Mil did keep lo 3 days in a row while my mother was busy the first day I walked in and lo was on the couch by hisself and mil was in the kitchen. I told her that lo can roll over and he is not to be left unattended on the couch by hisself. Second day dh went with me and he was on the couch again, and I told dh he needed to say something since he saw it. He then told her lo can roll over now and can't be left on the couch. Third day I walked in and he was sitting in his carseat. She said she would sit him in his car seat while he was awake and put him in front of the tv. This is a big no no to me, I told dh that he needed to say something. I brought over his swing so he had something to be sat in while he was there, but she never used it. Me and dh talked and we agreed after those days and her not following our wishes that lo would not be going over there anymore. We have not seen or heard from them since August.

Current situation: last night was halloween and every year I have always gone with my sisters & mom trick or treating. Pil know this. Last night was lo first halloween and we were so excited and dressed up as a family. I posted a pic of us on fb and fil commented on it and said "y'all couldn't bring him by the house". They live in a different town that is about 20 min away, and out of the way from where we were going. They excepted us to just show up out there, and we haven't talked to them in almost 2 months. I just don't understand it. I want to respond to his comment, but I don't know how. I want him to know that we are not catering to their needs and wants. We as a family will do our own stuff now and I don't think it is right for them to be mad thay we didn't go see them. How can I respond to get my point across, but yet not be rude so the other people don't think I'm a crazy bitch.