Just speak calmly, make eye contact, and give her all of your attention to let her know she's important. But don't make it seem like too much of a big deal or you may scare her away. If she does admit she has a crush on you and you like her, then ask her out on a date and see where it takes you.
Strike up a conversation if you want to get to know her better. If you and the girl who likes you aren't close but it's clear that she likes you, start small and bring up a common interest. This will break the ice, make things less awkward, and establish a bond that you can progress from.
When you spend time with someone and share vulnerabilities, it's easy to develop feelings of closeness and attraction. These positive feelings can develop into a crush, even when the other person is romantically unavailable. Traits such as kindness, intelligence, and a great sense of humor can fuel a crush.
When you're talking to the girl you like, you want to make her feel special. People like it when others take an interest in them and the girl you like is no different. Showing that you care about her thoughts will make her more interested in you, as a result.
Smile and make eye contact when you see the person you like.
This will show that you're confident and self-assured, and it will also show your crush that you noticed them. If you notice your crush is looking at you, make eye contact and hold their gaze for a few seconds, then smile and look away.
Playfully tease them often and smile at them frequently. Make sure to never cross the line and never be offensive as this might hurt them and drive them away. Tell them they look nice or that you like their sense of humour. Compliment them often and notice their little things.
If you want a girl to go crazy for you, then you have to make her feel special by actually taking the time to recognize her as a unique individual. Tell her, “You're not like other girls…” or “You're so different from your friends…” and make her see that she really does stand out to you.
In a nutshell: know how to dress to suit your personal style, smile (but not too big), maintain eye contact, stand up straight, be approachable and don't talk too much. The better part of physical attraction is simply the way you comport yourself.
Even if she isn't as polite as she could be, be the bigger person and accept the rejection. Just end the conversation with a simple, "Okay, I'll talk to you later," or something like that. When you see her afterwards, just smile and say hi.
Simply tell him you're not interested, but do it in a kind way, especially if you want to keep the friendship intact. He may not be able to only be friends with you, but you'll feel better knowing that at least you tried. You could say, “I'm flattered you feel like that, but I don't want to risk hurting our friendship.