@izzyrose,
You got nothing to feel threatened about as porn is just a sex aid, he loves you. Why don't you watch it with him so you don't feel left out. And then after awhile ask him would he mind watching it only when your together for awhile. It's only a problem if he stops making love to you. You say your sex life isn't great at the moment, well spice it up a little, I'd bet his face would drop if you came home with a porn vid and suggested you both sit and watch it, it would please him which in turn pleases you, try not to feel so threatened, they are only enjoying the view, he loves you. Men huh, just do something for him and see where it goes.