Perhaps it is just the temperature change. I know the heat here is creating really humid, hot air. Just be careful if you wish to place it back outside as they cannot tolerate full sun (direct sunlight); they will burn. You could just wait and see what the next set of blooms do. I have to say I've never seen blooms droop like that before but I would imagine if it stays inside and produces more blooms, they will be normal.

Planto

They're a bog plant and have a high water requirement. If you're putting it out suddenly into hotter drier air the plant hasn't had time to adjust to taking up more water. So the plant cells end up with a nett loss of water and become softer (sort of 'deflated') and the stem bends. It's a matter of adapting it slowly.