A bit of background:
I am a lone parent but still on good terms with ex/ex in laws. Two DC under 7 yo. Both ex/myself work full time.
Once a week (generally) ex ILs collect DC from school and mind them until either ex or I collect them after we finish work (around 6pm). Ex and I are very grateful as it means the DC don't have to go to after school care which they don't really enjoy. ILs are very happy with the arrangement because they get time with DC (on weeks when we don't need their help they come over just to visit).
In the last month ILs have forgotten to pass on important messages from school twice. Taken DC to shops after school and left DC1's book bag there twice. Not checked DC2's bottom after they pooped so left them unclean. Left the DC unsupervised on a few occasions (one time I came home early to find DC having water fight upstairs and ILs watching tv downstairs). And generally left clothes/toys/general debris all over my house every time they've been there.
This came to a head this week when I said to DC 'how did this house get so messy?' And DC1 replied 'when you're not here the grown ups let us do what we want'.
AIBU to be totally fed up??