So Bizarre - Clothing and Relative Visits

So, those of you along for the ride with Blue Eyes knows that he is allowed to visit his siblings/grandma (diff dads) and his great aunt with whom he lived before me, any time they want. They have been very flexible and considerate to me and limited it to once a month. (The only reason it is a drag is they both live almost an hour from me so even meeting half way is almost 30 minutes, sometimes longer with traffic.) So, every single time he goes to the overnight visit I pack 2x the needed clothes. Recently, our temps have been fluctuating immensely from day-to-day so I would pack a "warm" out fit and a "cool" outfit. I always pack extra undies and pants in case of accidents. And of course, a pair of pajammies. Well, every single time I pick him up, he comes home in clothes that I did not send! Now, with his Auntie, I can almost see because I know that she got a voucher for him and based on the "new" 18month clothes she has passed on to me (a couple of items) I know she didn't use all of the clothes for him. (This is the same relative that never sent any of his clothes.) So today, I pick him up from grandma. First, he was sound asleep. I mean DEAD TO THE WORLD asleep. That tells me that he not only did NOT get a nap but he played really hard. Seriously, he slept the entire 30 minutes home and I was starting to wonder if he had been drugged. It was 7pm but still. But the thing that most concerned me, was that he was in pajammies. Now, I knew that since we confirmed meeting place on the phone and Gma asked if it is ok for him to be in pajammies. What I expected was to see him in the summer pajammies I sent for him. What did he come home in? A footed, blanket sleeper! You know, those fleece like kind that are soft. Did I mention that it was 90˚ today??? And, both times with his great aunt it was the same thing. One day it was 80˚ and he came home in shorts, a long sleeved shirt, and a long sleeve jacket. Now, we keep it pretty chilly here and the only time he has complained about being cold was one day last week in bed, but his bed is over the air vent. So I covered up his air vent with a cover I bought, but am going to move his bed around anyway. The point is, after 5.5 months, his body has likely acclimated to the temperature here, so being dressed like that had him sweating. I just don't understand it. I can see where they might want to buy him clothes, but these aren't new clothes he comes home in. Often they are wrong size, and stained. And the clothes I send him in stay perfectly folded in his bag. I don't want to sound ungrateful for the help, but it is a PIA to keep track of clothes that they sent, and you know we have to do that and send them back with them, as long as they still fit, when they leave. So, what is up with this behavior? Do they know realize that it is almost insulting to me as if to say the clothes I send aren't good enough?