R.N.
First of all, your son is not old enough to understand sharing. You can try and force him, but you will only upset him and he is not going to 'get it' until he is about 3 (and even then it will be tough for him to share his own toys). I used to be a co-facilitator for a parenting program, and the one thing that my co-worker used to tell parents about sharing is this: "Imagine that a friend of yours asks to borrow your new car. You love this car and feel it is the best, most precious thing you have ever owned. How would you feel about 'sharing' your new car? This is how a small child feels about sharing his toys, but unlike us, he doesn't have the developed emotions and language skills to deal with it." At 21 and 7 months, the best thing you can do is only have out toys that you have duplicates of, so that if your son grabs a toy away from Kenny, you have another one like it to give to him. The 7 month old isn't going to care as long as he has the toy of his choice--it doesn't matter which one it is. As far as 'sharing' you, I'm thinking that Kenny probably still naps a couple of times a day, morning and night. Gavin probably only naps once in the early afternoon, correct? You'll need to schedule 'lap time' for each of them during the other one's nap. Also, if you need to hold the baby while Gavin is around, try and make sure he is distracted with something he finds really enjoyable--whether it is play-dough, or watercolors, or his favorite video, or whatever. This is not an easy assignment you've taken on--good luck! :-)