4. Be prepared for the basic questions.
Given your particular givens, you can expect certain questions to crop up, from "What are you majoring in?" to "How did you meet?" to "Do all your children have the same father?" Talk with your sweetie in advance about how to handle any sensitive questions--including questions that might not even sound "sensitive" to you but have a lot of family baggage attached to them. And you'd better both have the same answer if you're asked if you plan to get married.