Do you find it problematic for a person who kisses the of someone who wants nothing to do with them?

EX: My twin sister is mad @ me, & I don't know why. She even blocked my phone #. So I e-mailed her & asked her what I did for her to be upset, & my brother got mad & said it's wrong of me to kiss @$$. But that's my TWIN! Well, there was a lot of he-said/she-said stuff, & somehow my name got thrown in the mix when I had nothing to do with the situation. & now I gotta suffer. She was mad @ my brother to the point where she tried to KILL him! & she's speaking to him again. She sliced him with a butcher knife because she was upset that her husband left her hanging with 3 kids, & she's mad & trying to take my brother's girlfriend away from him. I think she's kissing up to him to try to get to that girl. We're 24 by the way. I'm just so hurt now.