lay with him at night and read him stories that he likes, play cars with him have one on one time with him , take him for a little walk, he is at the age where he will feel leave out he loves you that is why he is doing this,he wants you all for himself he is only a baby he don't understand, huge him, kiss him, I have a 4 year old boy to he don't fight me,but he ask me 100 times for day( mummy do you love me, I love you) he used to till me if I love him I will play with him,so I lay on the floor or sometimes crawl like a baby pushing a non operated battrey car or trunk all over the house, sometimes he want me to draw or colour with him, I also have a 6 year old girl I spend time with them both but the little one alway want me to spend more time with him , forget you are his mummy just for a little while and play his friend , pick up some of his toys that he likes most and play with him he will love that. sometimes in our world we thinks that we give them all but in there world its different they want us more then we think they do,you are a great mom don't give up, never give up love him he is your baby,he love you he just don't know how to show you it.my son love that I play his little friend .
Yes play with him, pay him attention, it is possible the other two because they are older get most of it, Does the 3 year old spend quality time ,one to one with you .There will be a reason for his behavior and it may be a good idea for you spend extra time with him read before bed, play games, take him to the park.If you are working and he goes to day care thats more reason to spend quality time with him..