That's an impudent behaviour. Next time they want to visit you, tell them you'll have an urgency and will have to go to another city/country for work or something else .Guests who over-stay their welcome.
We've Ali's cousin over from France. Which means 5 adults and a child sharing a 2 bedroom house.
None of the guests lifting a finger to help.
Not a single offer to help cook*, or wash up, though for the 2nd week, they did start using the kettle without asking Ali or I to make them a drink.
TV is basically never switched off; but I'm not sure anyone knew what it was showing at any moment in time.
I'm insomniac, and always wake up around 3.00-3.30 in the morning. I cope by getting up and doing stuff for an hour, then going back to bed, and I can usually get another hour or 2 of sleep. I can't do that with guests sleeping in the living room. Usually, I've gone to work in the morning before being able to use the living room for anything at all.
They've left the house twice - once to go shopping in Cheltenham, and once to go to the supermarket to get food they thought we should have had already (kids food, + some we did have, we just expected an entire round of brie to last more than 1 day. Apparently, brie is a thing they just eat whilst deciding if they want to eat anything between meals or not).
This is the 3rd time this year they've been to stay for a fortnight, with different combinations of 4 guests (this being the first with a child).
They arrived 2 weeks ago, and leave at some point this weekend - though there's chat that 1 will return home, and we'll have to take the other 3 to the airport NEXT weekend. We don't own a car, so will have to rent.
* exception being the 2 year old's meals - we weren't expected to do those - just tidy away and wash up afterwards.
ETA: Sorry, apparently, I really needed to offload onto someone!
Last time we were in guests, we cleaned and washed everything, brought gifts and food etc. Can't even imagine myself behaving like your cousin and his family