I have been in a stable relationship with a married co-worker for two years. I get some flak for it because he still lives with his wife and their 10-year-old twins, but the wife is aware he sees another woman, and she hasn’t had intimate relations with him for the last five years. He has talked about our living together when his children are grown and we both consider this to be a committed relationship; we do not see other people. My own twin sister is now getting married for the third time and has recently become a devout Christian. I was invited to the wedding, but my partner was specifically excluded. When I asked her why, she said it was because our relationship made a mockery of the sanctity of wedding vows. I find this hilarious coming from a twice-divorced woman marrying a divorced man. Her fiancé, who is lovely, is fine with my partner coming, and my sister has met him many times and has always been gracious. Should I simply attend without my partner, or should I refuse to go unless I am permitted to bring him along?