I'm in a similar situation I guess. There is a girl who wants to date me and she is extremely nice. I know however based on her family and cultural background that she would be looking for something serious and long term. Aside from the fact that I'm not really attracted to her (she's nice looking but not my type), a long term relationship would get in the way of my aspirations to live abroad. Like in your situation, she hasn't really come out and openly asked me if I want to be her boyfriend, so I can't just straight up tell her I'm not interested. I've been kind of just not reciprocating her interest, but it makes me feel really bad to do that.