qiqi,
my point is that we should not give up, not to have 2nd one bcos of that reason la...kekeke...of course if u plan for 2nd one, it's good too! in my case, I did whatever I didn't get to do with my #1 to my #2. eg. I bf her longer including all the night feedings
I dun quite understand how come ur MIL dun let u play with ur bb? just carry him, use a bb's voice to say 'grandma, I'm gg to play with mummy' and off u go. this way, u won't sound rude and at the same time can teach ur son new words.
find some activities that u can do with ur son that ur ILs can't. for me, I read nursery rhymes, sing action songs and play silly games with them. he needs to hear ur voice more often to bond with u.