Input from the old lady:
I concur with
@Howiestern and
@Fruitbat on this one although all the points are valid. My marriage relationship never got stale in 20 years and we were at it almost daily, often twice a day. Once in a while thrice.
The beauty of an LTR where desire resides is that ability to be honest about what really turns you on and having a partner who is on board with that.
Thing is building the required level of trust takes time and thus the sexual experience can deepen and improve in through time.
Sex with my fiancé is improving in this way as we progress. He doesn’t need to perform for me, he doesn’t need to stress about whether he’s impressing me or not…I think he looks magnificent naked and this inherent desire (which he also has for me) is the fuel that allows passion to burn. Sometimes it smolders, sometimes it’s a conflagration, but this is why desire is key.
For me, good or great sex with a beloved partner never gets old. It may get weird or funny or kinky or just plain hot, but never NEVER old. I will say too that I have a very high libido. I never say no to my man & at times want it more than he does.
Cheers.