I don't speak from experience, but I've heard have him use one finger to slowly get you used to it. When that's ok, use 2, then 3, just to stretch you out. Your muscles will get used to it and allow you to have sex less painfully(if any pain at all). Also be sure to use plenty of lube...there is no such thing as overkill when it comes to that

This is a vague question. I can assume it is because he's too big? In that case you can't really do much about it. Make sure he is paying attention to how you feel while also being pleased. This would be a tricky situation and communication is the key. Also, NEVER underestimate foreplay, it doesn't feel as good as sex but it get's you to where you need to be and when you do have intercourse you will be properly lubricated and probably more willing to take a little pain. Don't let him just rush in, that can really hurt. I say just communicate really well with one another and don't be afraid to try new things.