I live in a University Campus in the UK and I like one Russian chick who has a boyfriend
back home in Moscow.
We already built some rapport between us and I was very close to kissing her two nights ago in a club,
but instead I punched her guy friend

who came out of nowhere and started dancing and pushing me around while doing it. She got mad at me after that but seems not to be mad any more.
Anyway, she has been in a relationship with her bf for 2 years now, the good thing is he is not here
and she only sees him on holidays in December, April and Summer.
What is the best way to approach this situation, keep in mind that I want her as a gf.
How do things like this even work, lets say we get on together, will she just leave her bf after some time? What if she likes me and him too?
Regards