No I don't mind anybody eating beef in my presence.
I once consumed beef but unwittingly. It was a buffet lunch and I was having a bit of this and bit of that. I didn't check the description of the meat. It was like a kebab, I had one small piece and it felt a bit different. I went and had a look and found that it was beef. I simply stopped eating that and trashed the remainder.I did feel bad about it but it didn't bother me for long because I ate it unwittingly.