Sex life

My sex life with my SO has always been predictable and I don't mind because he pleasures me. Up until recently my SO has been a lot more horny and wanting to do a lot of different things with me. He also has sex a lot longer. I didn't mind it at first. But we both agreed sex wasn't really a big issue for us and he doesn't care for it. Now he's talking about sex and wanting sex more and more I can't keep up with it. It's extremely out of character for him. He's even talking about things that I don't exactly want to do (ex: anal) I'm starting to question his behavior as it is unusual to just want a lot of sex.(for him at least) Any one have thoughts??? I worry about him cheating or looking at other women.