BIL with DS ha become hyper competitive and mean to me since nephew started talking

[tumbled22]

My BIL is a 37y/o DS man that lives at home. He is a very competitive and attention-seeking person, which has always been fairly manageable for his family until recently.

My husband’s sister recently had her first child and ever since, my BIL has been obsessed with the baby, even more so now that it is old enough to talk. He’s become fixated on needing it to love him more than anyone else, and especially it loving him more than me in particular. Whenever I am playing with the baby and make him laugh, my BIL will rush over to us and physically put himself in between us to try to take over making the baby laugh, then turn to me and say how much the baby loves him and thinks he’s funny.

The baby finally said “uncle” for the first time and my BIL has become so obsessed with him saying it that he will follow him around asking him to say it over and over and over. One night he bragged about how he said it before he said my name and when the baby’s dad let it slip that he’d actually said mine first a while ago, my BIL got really upset and ever since he’s been mean and passive aggressive to me and won’t let me have any interaction with the baby without butting in.

I’ve tried talking to him about how these things aren’t a competition in the past and his parents sort of talk to him about it, but it just seems to be getting worse and I hate to say it, but it’s causing me a lot of personal stress to be around him. Any advice?