Does my dad's girlfriend dislikes me?

My dad split with my mother for almost a yr because of issues and he met with this dominican woman that works with him and they started going out. I met this women in November of last yr and everything was cool and we got along just fine, until february she just started to avoid me and doesnt really talk to me anymore. My dad lives with her and i come to visit everyday because I lost all of my fake friends and i get bored sometimes so i come to hang out with my dad. She has been acting very weird lately and my dad was talking to me about how she tells him that i dont respect him because he told me one time to pull up my pants when i cant help that my jeans tend to sag alittle and because I have tattoos and that i shouldnt be that way if i was to be his son and i thought to myself like what was that supposed to mean?? I felt really hurt by that and confidence dropped alittle. I'm also starting to suspect that her kids ( twin girls ages 14 & a boy aged 10) dont really like me as much either.. They get along very well with my dad and even call him dad ( He's crazy about them) but with me its like they dont like me as much. Why is this?? I would talk to my dad about it but he seems to be very happy with them and hes already taken alot of **** from my mom, so i dont want to give him second thoughts about his girlfriend, even though he did tell me that this woman reminded him about my mom ( miserable on saturday morning and attitude problem sometimes).. What can i do because i'm kind of starting to hate her, mostly because of her critisizing me for something stupid. What shouuld I do??