I have a crush on my best friend

Throwaway, as I think some people I know found my main account. By the way, English is not my first language so sorry if you guys don't understand something or if I mispell something.

Hi, so, as the title says, I got a crush on my best friend. But, I'm dating someone at the moment, whom I've dating from almost 2 years now. I'm no cheaters by any means, and I'm not trying to make any moves or to actively seek my friend more often. I respect my partner enough to keep myself away from a safe distance. Well, my best friend (whom I'm definitely not his best friend lol), has been always there for me, and giving me company or helping me with various topics. Ever since I met him, I've felt a little attracted with him - not enough to call it a first-sight love, though. But I just feel really guilty.

I really love my partner, I really do, I always want to be closer to him, and to stay together no matter what. But I can't help myself to still be attracted to my friend. I don't want to tell my partner - even if I should, as I know this will break him more than anything, he's such a great person and I don't want to hurt him.

So I'm doing nothing about it. I'm not telling my partner, nor I'm leaving him, nor I'll make any moves and cheat on him.

I just feel guilty, I shouldn't be feeling this, I want to stay with my boyfriend, but my mind starts to wander. My best friend right beside me, my best friend holding my hand. I just can't cope with this, it hurts to know I'm betraying my partner in a way or another, and I love him. I don't want to keep feeling this way, and go back to where I didn't have this annoying crush following me everywhere I go.

Thank you for reading, I will be reading/answering your comments <3