I am assuming , as you did not say that you are his father?, it sounds like a jealous issue he is possessive of you both and he usually gets one to one fron each of you, ignore the behavior , do not feed into it,he is simply wanting all the attention, try games and sporty and Fun, all of you, does he like board games the 3 of you can enjoy, do things together and if he gets bad tempered ignore it.