Will he stay this way?

DS is 13 months old and besides a few play dates, hasn't had a huge amount of interaction with any other kids. Tonight we were baby sitting a friends 11 month old DD. Whenever she picked something up or came near either DH or myself he would climb on her, snatch things off her, hit her and pull her hair. It seemed very much like a jealousy response, like a 'that's MY dad' thing. I'm almost 34 weeks pregnant and I'm worried he will react this way when his brother arrives! Do you think 'sharing' us is something he will get use to? What could I try to discourage this behavior?

Sharing is very much a learned behaviour (as you have probably seen, some people never learn ;) ) But yes, it is not something a 1yo is able to understand or deal with very well. It will take a while but he will learn it. Your DS2 will probably learn to share faster though.

^^ Nai summed it up well. You need to keep reinforcing positive behaviour & keep talking and telling them not to hit (or whatever it is) and why and show them how to share. Your DS will get there eventually

I agree, its probably age related and you just have to keep reinforcing sharing as he gets older but at this age I think distraction is the best thing, if he wants something someone else has distract him with a different toy. Im sure like all children there will be some jealousy and a big learning curve having to share you both with another little person but he will adjust. Don't be shocked if there are some tantrums and tears, praise the good behaviour, ignore the attention seeking and make sure he still gets one on one time.

And Nai is right second children are much better at sharing as they have never known anything different. My DD who is 3 tomorrow is much better at sharing than her 5 year old sister

Good luck with the impending birth of your DS and the changes in your families dynamics :hug: