In love with a girl who already has a boyfriend what are somethings i can do to make advances?

first of all I would normally never do this, but i have way too much in common with this girl and we have a great connection (i've never experienced such a connection with anyone in my life) to the point where it seems that a relationship is the only logical next step and we can predict each other's responses to each other, but she has a boyfriend, which puts me in a rather awkward scenario. I know the meet sometimes and he is one hundred miles away, so it's not like he would be able to interfere effectively. What are some ways I can make my intentions clear and find out what her boyfriend doesn't do for her? Any advice at all would help. im just so attached to her and this is something that has never happened to me before. we've only known each other for a short period of time, but i want to seize the day.