Back again, not obsessed really, just that sometimes threads run on in my head like conversations.
Imagine this - forget the special circs of the walk for now. Your wife announces that her friend could visit one weekend, Saturday night and Sunday. You say 'great, of course' because it's good for her to see her friends (even if you find this one a bit annoying). It's only one night after all, no big deal.
But imagine if, in her saying 'my friend could come' - the implicit assumption is that you will clean the whole house, change the sheets, plan, shop for and prepare a nice dinner, then act as charming host. Clear up (maybe she'll help with that?). Then, look after the kids the next day. Because of course it's normal for her to assume she and friend can go off and do their thing. This doesn't even need to be vocalised, or framed as a request, it's assumed. She might check in a presumptive manner 'it is ok if we go and do this isn't it?'. She will be surprised and might get a bit stroppy if you say no.
If she does offer to help, by doing some cleaning, cooking, or looking after the kids, that's really kind and putting herself out for you. You should be really grateful.
Now, throw in the walk - the big sporting event you've been training for and are looking forward to completing, celebrating with your family and hoping for a bit of a rest and perhaps a nice family activity the next day.
(Oh, she regularly takes a whole holiday away from the family, leaving you in sole charge of everything, for her sport. This is your one whole weekend dedicated to your sport - or so you thought).
Do you see how she might feel?
Do you see how very easy it is for you to say 'I wanted her to say "of course he should come, how nice for you". Which is a bit selfish of me. But it's what I think I'd have said if she had a good friend coming to stay on any day, ever.' How very, very different it is for her to say this to you - if she is doing all the work associated with either of you having friends over?
Personally I just don't get the 'default carer at weekends' thing, or the default doer of housework thing. Why would this not all be shared equally? Why would you not have equal leisure time, equal opportunity to take a weekend day to do your own thing, without it being a big deal, equal opportunity to go away for ten days, just because you want to?
What I would say, is that doing things more equally requires constant low-level negotiation, so good communication.