Anenome help

Need some help guys. I have a sebae anenome with it's mouth inflated and sticking out. Is it sick or is this normal? I've had it for about a year now. Water parameters are good and i'm doing a change tomorrow. The tenticals appear to be normal and it still has good color. It has decreased it's size slightly. As you can see from the picture (krill sitting on its mouth) it's not eating today. I feed at least twice a week with no previous problems.

All help greatly appreciated!!

 

Looks like it's just taking a little longer to eat to me. I would not feed it again for several days though. Twice a week may be too much or the pieces too large. Smaller pieces is always better.

Very pretty anemone

 

Thanks Corailline,
He's decreased size by about 25% but still has good color. The mouth still looks the same 12 hrs later.