Mil favouring sil child

[ifeelyoum]

My dc are 7 and 5 now but mil has never shown any interest inthem. She has given them birthday and christmas presents etc. But never played with them, taken them out and has said she will not babysit. Along comes sil first dc and we never hear about anything else. How she has had him all night and he has kept her up, how much she is helping them out . I cant hep feel annoyed and resentful. How shall i handle this, dp thinks ibu. Luckily I have my parents who love them

Have you heard of the golden child and the scapegoat? In this case your DP would play the role of the hero. Its pretty common for the hero to avoid rocking the boat, because when they rebel the family falls apart.
www.outofthestorm.website/dysfunctional-family-roles

So its unlikely you will get any support from your DP, and his inaction could have consequenses for your children. they need to feel that he has their backs.
Watch out that your MIL or your DP doesn't pick one of them to be the scapegoat, especially when they become teenagers.