My boyfriend's grandmother passed away

It's his paternal grandmother (of his stepdad that raised him), and the funeral service is on Monday.Yesterday his mother called him and told him that I wasn't going to be allowed to sit with him (and the family) because his step-dad wouldn't feel comfortable, especially with all his work buddies being there. This set my boyfriend on fire.His step-dad has always had a problem with him being bi, but it seemed like some progress was being made. I spent Christmas dinner with them and his dad gave me a present, a huge step.I don't like how my boyfriend always gives in to them and let's them walk all over them, especially when he knows he's doing it and it causes him so much anger.I tried telling him that if he needs me there then to just take me. It makes no difference to me where I sit, but if he wants me beside him then he needs to stand his ground. He doesn't want to make a scene at a funeral though.I would really like some advice on this. Should I push him to bring me? Should I just not go? What do you all think?TL;DR: boyfriends dad is uncomfortable having me at my boyfriends grandmothers funeral. Boyfriend is pissed but won't stand up for himself. Help!