Re: age difference?
^ How do you usually act when your mom tells you that she has invited guests whom you've never met before (let's say that it's not for rishta purposes)??? Ever been in that situation?
Don't you usually just dress nicely, say salam, ask how are you, serve the food if necessary, sit on the sofa in the living room with your parents and answer any questions the guests might have for you? This is what you'll be DOING.
I doubt that the guy will be asking you any serious questions in front of his parents and yours. Usually parents allow the guy and the girl to talk separately. If it even gets to that stage, that would be the part where you get to know him more.
When it's all over and you've breathed a sigh of relief, do tell us how it went.