It could also be her hormones kicking in cause, you know she was just making an NTR ero manga earlier with a dildo, and now she got some irl stimulation.
Could just be horniness or embarassment or both.
Damn... So both brothers are weak as fuck...
Just tell her to fuck off, and slap her if needed!
Like, what she gonna do?
Complain to little bro?
You warned your brother, he didn't listen, this is the consequences he gets.