Sometimes I think one of the most difficult parts of being a parent (especially a SAHP) is the 24/7 nature of the job. I love my boys, but they are ALWAYS THERE! When I go to my brother's house or my mom's house I would love to just sit and chat and have some time with the adults. Doesn't really happen, though, because the kids need attention.
As I was sitting by myself in one room of the house while they were occupied in another, I started typing. That's when they both decided to run in here and demand my attention.
I really get what you're saying. It's very tough when you never get alone time and adult time. We need that, too.
I'm guessing your MIL gets plenty of adult time and when your son comes to visit she is just so excited to see him! It's not really fair of you to ask her to not play and carry on with him. He loves it and she loves it and it is just so healthy for both of them and for their relationship.
It's not that she is disregarding your wishes for his behavior. Asking him to "not carry on and listen" is simply not an age appropriate expectation. He's 5, and 5 year olds can be expected to do that for 10 minutes - 20 if it's something they are very intersted in.
How about a compromise. Give your MIL more opportunities to play with your son. If you would like a chance to just hang out with her, do that while your husband plays with your son.
I really do understand wanting adult time. You just have to figure out a realstic way to make it happen.
I actually teach, so I work during the year and am a SAHM for the summer. One of the best things about it is having the occasional lunch with my husband. Both of our kids are busy (and happy) and we can spend some uninterrupted time together. Love it!
Hang in there. These early days can be draining on us, especially the SAHP's. It won't be long before he's in school and you can breath again.
So sorry to hear about your mom. I can't even imagine the pain your going through. Talk to your husband about ways to do a few things for yourself. I think that will really help you as you grieve.