I do think your DH is being unreasonable. Mine are 16 months apart and the same ages as yours so I can undertsand. Our weekends go a bit like this: We take turns at the weekend to have lie in. In boring more detail: Last wend - OH stayed up late on Fri, so I got up at 7am with both kids. He then gets up or I send kids to 'wake him' around 9.30/10am, depending on how 'easy' I'm finding my morning! The older one watches kids TV quite happily while munching breakfast and I have to playdoh/paint with younger one. The next day cos the kids got up later - 8am, I'd had enough sleep so actually got showered/dressed but didn't go downstairs til 10am as my 'lie in' - just did pottering/admin/bit of reading upstairs - kids thought I was still asleep so didn't disturb me. OH then wanted some time, so I offered him the option of entertaining the kiddies further or doing an hour of housework - sorted.
I must admit, I'm not a housework person - I only squeeze in about an hour at the weekend. We do a daily quick hoover - we have to cos they're like lil monkeys when they eat - what I'm saying is, when I have them all week I don't ever try and do any housework. OH washes up when they're in bed and I then cook for us. Everything else waits really. They do squabble loads though which is relentless and super exhausting.
We have no family/babysitters/playdates etc...and it is so hard. Finding this age a real struggle.
So, after lie ins etc....and vegging at home might head out round 12ish - maybe have bit of lunch out altogether and take 1 kid each sort of approach - libary, soft play, park, forest/river walk, swimming - just OUT - I find it SO much easier being out rather than in. Easier now that 2.4 yr old can often do without a sleep in the day. But, I am also dreading winter, too many rainy days. Even if we go for a walk, that can last a good hour or so if we aren't 'trying' to 'get' anywhere IYKWIM - taking it at their pace with them having a bucket each to collect all sorts of useless shit treasures works well.
Are your evenings your own? Both kids are normally in bed by 7.45pm so then it's me and OH 'turn' - watching boxsets of DVDs, reading to each other or playing a game rather then turning TV on.
Some evenings (maybe twice a week) I might get 30 or 45 mins when OH gets in at 6pm (on weekdays) - then I might do something but be back for bedtime - go for a walk by myself, or a coffee - just for the sanity! I do the food shopping once a week and love it. I go alone around 6-7pm, OH has the kids - he doesn't drive so him doing the food shop would not be an option. I used to find food shopping the dullest thing ever and used to do it online, but now it is such a welcome break! 