I know this is a long read but i would really appricate honest feedback

There is a girl (18F) at my school. Towards whom I (19M) am extremely attracted towards. The first time I saw her was when she was sitting on a bench on campus with her camera doing something. I mistook her for someone else so it was a small interaction but enough to make me remember her and notice her. Tbh I didn’t think much of her in the interaction since I’ve mentioned earlier that she isn’t very good looking, it wasn’t until later on when one day I saw her walk past me and I got a view of her from the side and back when I began developing attraction towards her.

Let me describe her: Now she isn’t the best looking in fact you can argue that she is kinda unattractive. She has a round chubby face with puffy cheeks. Average lips and big nostrils. Her hair is usually in a single braid at back. She has a chubby body. Her breasts are not super large. Though she is kinda chubby her breasts are the normal size for girls her age. (She is probably 18 or 19.). However, the part of her that I really like is her backside. It can be described as big, round, and giggly. It’s not even like she has super thick thighs. Her thighs are also pretty average but when it reaches her buttocks there is huge hill inflation. NGL Puberty has been exceptionally kind to her on her backside. This gives her body a shape resembling a mature middle-aged woman and I feel it is this that makes it so much more attractive. Also from the side angle, the hump of her butt pops out like a huge hill in a valley.

We go to a private school so here we have a uniform. In the girl’s uniform, the way her womanly butt shakes left and right when she is walking drives me crazy. Now I am a pretty fit guy. I got to the gym and have a pretty athletic body. I am also a virgin and haven’t been laid yet. I really don’t feel much attraction towards the fit cheerleader-type girls in our school even though they look pretty attractive (some of them even having done plastic surgery). I am a very confident guy, I feel that if I talk to her we might become friends fast.

She isn’t really socially active. I have only seen her with 3-4 other girls and never with any guys. Her friends are just as unattractive in looks as her in my opinion but she is the only one with such a mature and ripe body. This makes me feel a little more confident that since she has no other guys in her life she might equally be enthusiastic about being friends (and possibly lovers at some point in the future). However, I’m still unsure of how to get started. I don’t want her to feel creeped out by me as some random guy flirting with her for no reason

This leads to two of my questions.

1. how should I approach her, usually the girls I’m friends with have something in common with me i.e. same society, class, etc. However, she has nothing of that sort. Even our first interaction was accidentally so the fact she is just a girl at my school I have nothing in common with her so how do I approach such a girl? I regret not making small talk with her in our first and only interaction. If I had any idea she turned me on so much in the future I would have tried to make the best of that moment. Maybe we would have even been friends by now. At that time she was just an average-looking, chubby girl. I had no idea I would fall so badly for her out of all girls.
2. Secondly, I want to know if I am immoral for my reasons for liking her? When we first met I wasn’t attracted to her. It wasn’t until I observed her body that I began developing feelings. I never felt any sexual attraction towards any of the girls around me despite them being so pretty. But the only reason I like this chubby girl is becuz I like looking at how her butt shakes what she does something as simple as just casually walking. Does feeling attracted towards a girl because of her bum make me bad ? should I stop?

Though I swear I want more than just sex from her. I wanna know more about her, I wanna know her hobbies, her habits, and diet, etc. Just imagining myself holding her hands with we stroll and sitting close to her on a bench makes me happy. Though physically we would make an odd couple i.e. I’m tall and athletic and she is short and chubby I would still love to be seen with her and have no shame being known as her boyfriend. In fact, it will make me proud and happy.

I will admit Though I do have some naughty thoughts sometimes such as fantasizing about how she will feel touching my abs or imagining holding dirty conversations with her as we look into each other’s eyes such as myself telling her how sexy her butt is, to her face. I usually try to overcome such sexually suggestive thoughts as I know what comes next and I already feel ashamed enough for my reason for liking her in the first place i.e. her body.

So am I bad and wrong for the reason which sparked my love for her ? and if not then how should I approach her? Funny how she has no idea how much she has rocked my world, she probably still thinks she has her 3-4 friends in school. I doubt she even has the slightest clue that she is someone’s crush. I just wish the reason that sparked such emotions for her in my heart were a little less dirty.