Family forgot my sons birthday

Not sure if they forgot or just don’t care but it honestly hurts our feelings. They don’t forgot our daughter’s birthdays, just our sons.

We very low contact with my mom and thus very low contact with my two eldest sisters. They’ve always been a mouthpiece for our mom so it’s not really a shock.

No matter what my relationship is with my sisters, I will at very minimum send them a text wishing their children happy birthday. The niblings are just kids, and shouldn’t lose out on birthday love because adults can’t get along.

My bio dad who just came back into my life after 21 years remembered my son’s birthday and called to say happy birthday but my mom couldn’t be bothered.