MIL lives a few hundred miles away and visits every couple of months for a week at a time. (It's too long for me really!). Visits are always instigated by her and at times that suit her. Occasionally we have to say that certain dates don't suit us but it never goes down well. She will always push back and give reasons why she can come anyway, or try to make my DH feel guilty.
We generally let her visit when she wants unless we have other things going on. If we have plans that are taking us out of the house all weekend then it is pointless for her to come and stay. She is unable to accompany us to most of these things. If we went and left her at our house we would end up feeling that we had to hurry home to her. She would also end up trying to persuade us not to go,or pester us constantly to see when we would be back. So we tend to just say that it's not a good time for her to visit.
However, she just doesn't let up and it's really starting to get to me. She has decided that she wants to visit in a couple of weeks (we only saw her 2 weeks ago). DH has told her that it's not a good time as we have things going on and he may have to travel for work. She still won't stop pestering him about it. She just keeps coming back with ways to make it work.
We feel guilty about saying no but there's just no respect for us, or our wishes. She has decided she wants to visit and that's that. Whatever reason we give she bats it back. This happens every single time we are not available on the dates she decides. If we suggest other dates that do work for us she will say that she has other plans. We are expected to make the dates she wants work, but she never tries to change her own plans to fit in with us.
As usual DH is ready to relent and let her come, which always bloody happens. So AIBU to insist that this time no really does mean no?