Stuck in a imaginary relationship

Although my (not small) experience with relationships, I find myself in this stupid situation where I'm cluthced in this enormous need of communication with a specific man. We are both in serious relationships. We've met 4 months ago and he was the one who started showing a lot of attention towards me. We are both artists and he repeatedly asked me to make some small projects with him. And he was very persistent. He showed me multiple times that he likes me in a special way. It made me uncomfortable at first, but later I realized how much in common we have and how differently he's treating me than the person next to me.

If you are an artist, you will know how rare is to find someone with whom you can create in the same way, someone who understands you without words, someone who inspires you to creat when you've been indifferent to art in years. And all of you know how rare is to find someone who sees life like you do, someone who feels like a friend from the first moment you've met. Someone that can teach you, when you were always like a mother for your 5 years older boyfriend.

So I'm stucked. I don't feel the butterflies in my stomach and I want cross my moral standarts, but I desperately need to talk to this person. I have a big, big, big lack of proper communication with my boyfriend, I've had it for many years. And this new man is super busy working, so he just doesn't have the time to talk with me.

So, even if that he's still showing this special interest in me, he ignores almost every try I make to start a deep conversation. And I'm so exhausted, I feel so small. I will appreciate some advices how to manage this :( Thank you!