Can a Male Betta Live With A Oto Catfish?

I have had a male betta for about a year, and I am almost positive it is in a 2.5 gallon tank, the tank box said it was special for bettas. I put in a oto catfish, but before I did I put in a special divider so the betta is apart from the oto. My betta won't take it's eyes off of the otto, will it be safe to remove the divider? And I am NOT exaggerating when I say the betta WILL NOT take his eyes of the oto! How do I know if the betta is ready to attack? Will it hurt the oto if I take away the divider? What should I do? Please comment, thanks!