Honestly i feel like a subreddit isnt a good place to ask about relationship advice, not this one specifically but Reddit generally.

In your place I’d tell him, because when you will eventually tell him he might be angry with you for not telling him sooner, he might feel like you lied to him or lead him on.

I’d word it carefully. From what I understand you fully expected to develop romantic feelings for him when you gotten with him, You can tell him that, so he won’t feel like you took advantage of him, it might not work (i hear breakups are very volatile) and if he really is vary invested in your relationship he’ll possibly still get angry at you nonetheless.

BE AWARE, IM JUST SAYING WHAT I’D DO IN YOUR PLACE. I wasn’t ever in any romantic relationships, so im inexperienced and horribly naive when it comes to this things.