i just cant bring myself to like her

i cant explain why but whenever he mentions his gf, i just feel nauseous and disgusted and want to switch off her image just so that i can get over the disgust. i simply dont like her. i dont hate her but i dont like her. and i cant imagine liking her nor can i conjure much motivation to try think something sweet and pretty about her. i dont want to be in her presence; the thought of her coming over makes me want to run far away. if not possible, i ll stay in my room and not want to breathe in the same air as her. why is this happening? why is she invoking such reactions from my body?