I don't have a ton of advice for you but have you considered waiting until round two for this action? I know with my wife, if she wants it in a way that I find especially hot, I can't do it if I haven't come very recently. Or to be more accurate, I can do it, but won't last very long. Granted, now that we have 3 young kids, having the time for multiple rounds of sex isn't quite so easy.
There's always desensitizers. You could wear a condom if you aren't already.
Going hard and fast is a rare thing for us as neither of us are really all that into it so alternate positions are out of my knowledge base.