Advice with bf

So my bf grandma that iv have been introduced to 2 times is in the hospital. I do not feel comfortable going to see her but fully support him going and me doing other things. I myself see it as disrespectful for the fact shes in the hospital and the gf shows up. He has thrown his brothers bf of 6 months calling her grandma and his mom, mom at me like i should be doing that and im not ok with it. Its not my mom ir grandma. We have been together year and a half.