My advice to you, would to try and be more socially active with lots of people instead of just her, so you can be more confident in yourself and improve your social skills to. You have to prompt people to talk to you and make an effort to go out and do things and meet new people, because the likely hood is its NOT going to happen the other way around. Even if you find it hard or anxious to ask people to go out and do things or even just talk to new people, you have to suck it up and do it if you want to be happier in your social life and you'll feel much better much quicker! And I said with lots of people, because if you JUST try and talk to her more you'll find it harder and its not gonna be good for your self esteem either just chasing one person around to be friends with With things to talk about, maybe look at what she likes and what her hobbies are and find a common interest, and then work off of that. Maybe shes into films, or art, or a sport that you both like, maybe you could both go and do something that you both like together. Asking out of the blue might be a bit odd, probably best just to mention 'are you into blah blah?' after a bit of idle chatter instead of a really direct question out of no where. If you get on well enough with her and can work up your confidence maybe you can meet some of her friends and get into a new group of friends even! Just make sure not to.. Cross the line, in asking to meet her and stuff, because as you said you don't care about going out with her and stuff, so you dont want to piss off her boyfriend and CERTAINLY don't want to end up looking like a creep, so just play it cool. The sooner you start trying to talk to more people the better, life's to short to just sit around waiting for good things to happen to you, and as you get older you'll have less and less time and opportunities to meet new people and experience new things, so try and take a moment to look at your life and what you want to achieve and do to be happy, then jump right into it! Good luck dude,