My ex was 30 and his libido was like a roller coaster. He would be horny for a few weeks and then he wouldn't be horny for a while. I was 40 at the time and my libido was still at a constant high all the time. I would get erections all the time and I would usually get off twice a day. When his libido was low, he would still help me out. He did different things to help. He would suck me off, take me to a bookstore/bathhouse and watch me play with other guys or he would fuck me with dildos. But one thing that I was grateful for, he (or both of us) would invite guys over and I would play with the guy. My ex would either sit in the corner and watch or usually he would hide in the closet and watch the other guy and me. He loved watching me and I really got off on knowing he was there but the other guy never knew.