Back pain and sex!

Hey Guys,

I thought I would post here because I think maybe you would know best. I have been with my boyfriend for almost 3-4 years(yikes) we have one child she is 3 months old and wonderful. But our sex life isn't as wonderful. He has a dislocated disk in his spine which is pretty painful for him. This is where the issues start in our sex life. He can achieve all the main sex positions(missionary, Doggy style, side by side, girl on top) but once there is something different or odd for him it starts to hurt his back. I am getting very bored with all the same positions over and over again. I can also see he that he is getting bored he has said a few times he wished sex was better. So I was wondering if there are any tips you guys can give me to help us out. It is just really frustrating because I want to have good sex and I see things on porn that I want to try it but it hurts him. Such as sitting on a chair or couch and his tushhi is out a few inches off the couch and he has all control.

Hope you guys can help!

Thanks:)