Should I talk to her Gram about us?

ok I know I asked a lot of questions and stuff, but I need to ask for more help

ok my girlfriend said she wanted to take a break until tuesday. now today right now she is at the mall with another guy and I cant stop thinking about it, she told me she wanted to take the break and she dont know where she stands with us and where those 2 stand thats why she wants to spend some time with him to see whats sparks, then tuesday she will make her decision. now when I ask her questions so I can know whats going on she gets mad and either hangs up or dont talk she told me to stop worrying because nothing is going to happen but if it does happen (s*x that is) then thats the reason that she took a break so she wont hurt me as bad but she promised that it wont happen and also its just to the mall and she got her best friend with her so I dont think anything will happen. but she talks to her gram about the whole situation and since her gram said I am the only boyfriend she ever had that her gram likes then I was wondering since my girlfriend wont tell me whats going on and her gram does know should I call her gam while shes at the mall and see what her gram says and get any advice off her gram or would that be a bad thing asking her gram for info ad advice… like her gram told her she was stupid for wanting to break it off with me and her gram wants her to stay with me so should I ask the gram for help???