So me (20m) and my partner (20f) lets call her Bell, have been in a long term relationship for 2 years. We are both madly in love with each other. We both value healthy communication above all else and never have had issues talking things through.

Well recently Bell started their first year of University, and I was going into my second. During my first year we never had issues making plans and spending time with each other. I always made sure despite my studies to make time for them and grow our relationship. However; ever since Bell started University they've had a lot of trouble finding time for our relationship. I don't blame them, I think it's good they are taking their education seriously. But it hurts nonetheless.

I've been feeling lonely without them and it's gone as far as not receiving any update from them for a whole day (which is something that's never happened). At the same time my bestfriend, let's call her Ace is in the same classes as me and always wants to hang out, and go do things. Bell knows about Ace and likes their company too, but recently I think I've begun to develop feelings for Ace, really strong feelings. Which has made me feel terrible because Bell and I have been in a Open relationship, no feelings attached. I've discovered with myself that it's because Ace makes me feel things and does things with me that Bell otherwise can't make me feel or can't provide me. Bell loves staying inside and is an introvert, while I love going out and partying. It's because of all this (and a lot of thinking and talking about it with Bell) that I wanted to propose the idea of trying Polyamory, Or that I'm polyamorous? It's still all new to me.

When hearing this proposal Bell immediately shut it down and told me that Ace is off limits. They didn't even want to hear my reasoning, and when i get to explain even a little they immediately go against it without explaining. I need advice on how to proceed, because I don't want to stop seeing Ace and cut them off. But I also don't want to end my 2 year relationship with the person I love.