Scripting help please

my W is away with OM tonight and I've realised that its highly unlikely she will make it back in time for the kids swimming tomorrow (trains dont run early enough). she might surprise me and be here in time.

not that i'm ok with her being with OM but I do object to when this interferes with the kids lessons (and they love it)

My wife will come up with some sort of excuse (overslept or whatever). Is there a sensible way i can respond assertively - id like to have something in mind.

I was thinking something like.

'we both know that you are lying although what you do is your business as long as it does not affect the kids. In future when you make arrangements please make sure you consider the kids schedule as it is not fair to let them down like this.'


Both mid 30s, 2 young kids
BD 7sep14
XW moved on long ago, now living with OM1
D paperwork in progress