That's the way all good mother's are, maternal instinct kicks in and children come first.
However, you could always consider the fact you have "4" kids,...... including the skyline, which just needs a little more love and attention than the others... lol.
Just explain to the kids that their "big brother" needs new clothes (paintjob) first, and that they will just have to be naked for the next few months, and in terms of the bunkbed, they can just sleep on "big brother's" lap (aka the backseat).