Personally, I would not house them together (I'm not claiming to be an expert here, just my opinion). I would think it would be difficult to tell who did what when they are both in the same cage. Suppose you find a particularly nasty poop in the cage one day or some blood etc... There would be no way to know who did it. If you like to keep records, having both together would make that difficult too. And if one ever came down ill, you have the potential of the other snake coming down ill as well since they are housed in the same enclosure.
Also, with the snakes being several years old, are you prepared for eggs should they decide to make a little nooky when the lights are out? You said you weren't putting them together to breed, but do the snakes know that? 
>>i have had my bp's for a couple years now, but i was wondering if i could put them in the same cage, 1 m and 1 f...not for breeding but for permanent. i have heard yes and no....i tried it for a while and it seemed fine, they curl up together all the time, plenty of space, 4 hides, but they both stay curled under the water bowl (it is a hollow dog water dish), the male eats just fine, but the female will not eat, i take the male out and put him in a cat carrier about an hour before i feed her, but she will not eat, i suppose this means they should not be housed together?? any ideas or experience with this??
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Amber
Boas
1.1.0 Colombian (Austin & Ava)
1.0.0 Suriname (Aloysius)
1.1.0 Albino (Bo & Daisy)
Balls:
1.28.0 Normal (Tucker, Taylor, Big Eva and girls)
1.1.0 Pastel
1.2.0 100% Het Pied
1.0.0 100% Het Albino (Bubba)
0.1.0 66% Poss. Het Albino
Corns:
1.1.0 Amber
1.1.0 Butter Motley
1.1.0 Crimson
1.1.0 Ghost
1.1.0 Hypo
0.0.1 Normal
1.1.0 Okeetee
1.0.1 Snow (Aiden)
1.1.0 Sunglow Motley
Milks:
1.1.0 Hypo Honduran (Damien & Lucy)
0.1.0 Pueblan (Marishka)
1.1.0 Sinaloan
Other:
2.1.0 Dachshunds - Dakota, Montana, & Cheyenne
2.0.0 Ferrets - Bailey & Keyta