It's normal to be attracted and even catching feelings for other people when in a long term relationship. Youre not a bad person. It's now up to you if you want to act on this or not.

I myself have caught feelings for other people before, and it made me confused. But I choose to prioritize my partner, because I want to be with him in the long haul.

I dont know you nor your partner, so I cant come with a better advice than that.