Ball Python sleeping stretched out?

Normally my Ball Python loves to sleep curled up in his hide that is on the top of the UTH (hot side). However, for about the last week he has been sleeping stretched out across his enclosure, with his head poked inside the "cool" hide and his tail inside the "hot" hide. I poked him to make sure he was okay and he just pulled his head out, looked at me, and then stuck his head back in the hide. At first I thought it was just an isolated incident, however he has been doing this same thing every time he is in his enclosure for the past week. Prior to this, he always would sleep inside one of his hides, ocassionally he would soak in his water bowl for a couple hours.

My set up:
55 gal tank
3 hides - 1 on hot side, 1 on cold side, 1 in the middle
1 water bowl large enough for him so soak in
2 branches
2 rocks
3 artificial plants
Newspaper on bottom of enclosure
1 UTH
1 Heat Lamp
Humidity 50%-60%, 70% when shedding
Temp: 85 degrees average, UTH gets about 90 degrees and cold side is around 75-80 degrees

Is this normal/okay for him to do this? Is there something wrong with my husbandry that would be causing him to do this?

Seems fairly normal to me. He is obviously comfortable in his tank if hes sleeping/relaxing outside of his hides.
Just keep an eye open for anything really unusual. But he seems as though he is acting "the happy snake".

I have lots of ball pythons that won't use their hides for parts/most of the year. Its just on their preference weather they want to feel extra secure inside the hide or not.

Do you have anything regulating your UTH? What are you measuring temperatures with? If your UTH is unregulated I can guarantee that it is getting too hot and your snake might be trying to cool off.