Ya know, one thing that helps is to try not to let your hurt fester into no action. You can have things at your home and invite them. You can invite them to your sons events such as a baseball game. You can ask your husband if there is something special either his mom or dad can teach your son such as if one likes to do science experiments, or is good at hitting a baseball, or is good at making paper crafts, or is good at writing poems, whatever and then ask them to help your son as a way for them bonding.
and if they are still disinterested, send out a monthly or bimonthly (every other month) newletter to them of what's going on with your son in his life (X started school last week,. he reports that he really loves it and enjoys story time the best. Here is a picture he drew for you. He's starting soccer as well" etc.
Then you've taken action. Don't get hurt feelings but rather just involve that at some level even if it is one sided information. good luck
I been married for almost 2 years and it's very hard on me that my in laws dont accept me at all and in a way I feel like they don't accept my son and know I'm expecting again it just overwhelmes me. I have try my best to build a connection with them, but they won't give me a chance. Another thing is that they tell my husband that he made a bad choice in marrying me. And I feel like my kids are a mistake to them.
I know what u mean it took years for my inlaws to accept me I would even cry to my husband about it 6 years later its better but were the ones that go visit 95% of the time they usually come over on holidays or special occasions