A very common problem when your relationship becomes serious is whether your family will approve of him/her. Even for couples who 'don't care' what their parents say, it is still a nice feeling to see your loved ones happy together at a X-mass dinner (or at the wedding ;)).
That's why it would be helpful to know in advance if your mom can have a chat with your girlfriend or it will be a total disaster. Would your dad trust your boyfriend to take care of you or he will never accept him as his son(-in-law)?
Maybe you should give it a try and calculate your parents' compatibility with him/her. It will save you some nerves the days before you take on a trip home to meet the family. It might also help your partner relax ;). If not - at least you can have a good laugh!