This is probably a little unrelated but I work with a devout vegan who is always condemning everyone for their chicken sandwiches and milky teas.
She lost the plot today because someone ate her soy yogurt and went on a huge rant about how we don't care about animals and the environment. How we don't need meat to live etc etc etc
Everyone is tired of her constant vegan advertisements but we just let her be because it's the right thing to do. If we call her out it'll cause friction in the office and create an icy atmosphere, if we report her she may be given a warning and it'll affect her record. All we can do is just be British about it and awkwardly smile and put the kettle on.
With regards to the pro gay posts, you have every right to have your reservations but they have every right to express their support. Just try to ignore it and if it bothers you that much maybe you need to address why it gets to you.
I think your comment is relevant to this thread.
Your workmate's behaviour sounds very challenging to other people. Quite religious in its fervour in fact. It probably gets to me because we all us kids had a standard Catholic upbringing, attended schools etc. Pro-homosexuality position is an obvious "fruit" of non-Christian worldview.
You jogged my memory of other issues my sister has preached upon - minority rights, aboriginal rights as well as gay rights. It is something that is very common amongst social workers, always sticking up for the underdog.
There is a time and place for everything, but it gets quite tiresome for people who do not work in her field, have never knowingly hurt these groups personally but still get talked at as if we have somehow oppressed [fill-in-the-gap] people.
I remember a few years back her getting quite preachy at me for saying negative things about aboriginals, as if she knew more because she had worked with aboriginal women elders. I lived next door to one family in a outback town for six months. They even gave us several red and black dot paintings as presents to my boys.
They were OK until their relatives came to stay, then the tribe fights, domestic violence and drunkenness that the cops took their time to respond to after our calls "because it was THEM (the aboriginals) again". Thankfully towards the end of the year they went walkabout (they all disappeared), and we told the Defence housing staff that our house (we rented) shouldn't be for army personnel any more if possible because they were that bad.
But what I said didn't matter, she knows more because she is the social worker. I only lived with them.
So my sister is as bad as me in her fervour about issues we care about.
I keep it semi-anonymous online though and I think I have never told (or typed) anyone off for "not thinking the right way, according to me".