As has already been said, dreams are just dreams. Don't worry about it. In REM, your brain will cobble together all manner of things (usually in a way which doesn't make much sense) in an attempt to resolve any lingering thoughts or ideas from the day before. As Shannon says, what has most likely happened is you have, consciously or otherwise, been concerned about the fact your girlfriend is also your pastor's daughter and possible issues this may cause, and this has crept into your REM in this way. If anything, the fact that you acted as you did in your dream reinforces what you've said about your attitude towards your girlfriend, so that's something positive to take from it. Outside of that, there really is nothing to worry about.
