OH is in the forces, lives on base 50 miles away in a room with an en-suite and he has a cleaner. He has 3 kids, none of them live with him. He stays here every weekend Friday to Monday.
I work full time I have 3 kids who live with me and I have my own 4 bed house (over 3 floors). The house is mine not jointly owned.
OH's kids come and stay here a couple of times a month. We split the food bill when he is here but I pay the mortgage, gas, electric, council tax, TV licence, phone, Sky, broadband etc etc.
I get the house ready for him and when they come his kids. I also do all the cooking as OH cannot cook 
. Essentially it is gradually becoming his home.
I am not anal about cleaning nor am I a complete slut - my house is lived in although sometimes things slip a bit. Due to simply not having enough time, and not really needing to live in a show home. Admittedly my 13, 11 and 8yr olds should help more, I am trying to get that into place gradually without introducing a regime which involves me barking orders at them about washing up, homework etc the minute they get in the door. As a single mum I would like a good balance.
Recently more and more OH has started nit picking about domestic chores I haven't done in my own home and having a go saying I should get my kids to help out more - to the point he has begun to start on them a bit himself when he is here at the weekends, yet not making his own kids help either (ok 2 of them are only 6 and 4 but there are little things they could also do to contribute, just so there isn't a massive divison between his kids and mine). Often when his kids are here he spends a lot of time on the ccomputer downlaoding stuff while I cook etc .
AIBU and to feel resentful and pissed off about the way he is behaving and how do I respond and make my point without turning every minor domestic chore into a row???