Pain

I suggest you and Dave start using some ky jelly for the second round.

We use this all the time, it helps a litle, but not much, it's really frustrating, as I want to be able go all night long for him if he wants.

internal pain? external? when you pee? sorry, but that all can mean different things... i really sympathize--i've had some "ouch" experiences myself! go to your gynecologist. sometimes pain can be more to do with some other (internal) issues rather not enough lube.

Astroglide.

My gf usually complained of soreness after about 40min +.
Other than take a break I don't know what you can do.
I knew one of my buddies gf's would take muscle relaxers before she came over and they would go at it all day. Talk about a find!
But anyways, KY would only help if you guys don't have enough natural lubricant and its just the friction that hurts. If its something else I don't forsee a good solution.

You could go and see the doctor, but some kind of pain is quite common in my experience with a smallish number of female partners. If the first time is pain-free, then I don't think you should worry at all. Think back to cave-man days - do you think we are designed (by this I mean evolved, for all you conservative christians ) for 6 hour marathons? I don't think so!

Second time around there are many other things you can do!