try dropping the cory food in the plant stalks or something, most male bettas dont enjoy getting all tangled up in plants and the cory will have no problem finding the food then.
Most bettas must be a lot easier to deal with in such matters than are mine.
What with Loretta being ladylike and Lancelot being knightly, and newfishy's fishy's being just plain sensible, slower-eating fish can safely graze, with such clever precautions.
There must be a more civilized betta strain, not available in Winnipeg, Canada, careful not to get scuffed or to do anything to mar their finnage.
Sigh. And I get the rowdies...
I think I must have the plant-stalker strain, (sorry, mandatory pun) hunting the ground, swimming through everything that has a between, or in some cases forcing their way through the underbrush (or overbrush, if I can use that phrase in describing tall plants) so determinedly I sometimes worry they'll get stuck.
No wonder my most active boy, the one with the most beautiful, flowing tail, ripped his near the base and wound up bald-ended a while back.
I swear he was relieved he could move faster.
Maybe mine just aren't concerned about appearances, or something.
Or they just know 'Mum' thinks they're beautiful no matter what - and that if there's food anywhere in their tanks, they're finding it first.
And if there's nothing else, they may find a nice, tasty chunk of once-lovely tail...