I'm in a difficult situation, anyone got any advice?

My boyfriend and I have lived together for about four years, and we're planning on getting married one day. My parents are Catholic, and I was brought up going to church every week. However, I'm not very religious and stopped going when I left home, and boyfriend has never really went to church. My parents have no problem with my partner, in fact they get along great. They are always making digs about me not going to church, but nothing too bad. But they have since told me that if we get married, and we don't have a church wedding they wont come. I'm really hurt about this. I wouldn't mind getting married in the church, but I don't like the way I'm being coerced into it. If my parents had simply told me that it would mean a lot to them if I had a church wedding then I would have happily done it for them, but threatening to not come to their own daughters wedding unless I have it where they want is out of order I feel. I don't really know how to handle this situation. I'm actually very close to my parents, but their attitude is really upsetting. Has anyone ever experienced anything similar, and if so what did you do? Thanks for all who read and answer this, I know it's a bit rambling!