People often talk about mismatched desires leading to ruin and the importance of finding someone compatible and then being perfectly happy for the rest of your life.
In my experience, this is a crock of poop.
I'm not talking about the drastic cases of one person being vanilla and the other kinky, or when both want to be subs and not Dominant at all, which are major incompatibilities. But when one person desires S/M play at the level of "Oh, that might be fun to do some day soon" and the other person desires it on a level of a crack addict it can be hard when the crack addict is a slave and it hurts to even ask (not hurts in a fun way, either, it hurts in a "just sucked all the fun out of life" way).
I have seen over and over for my friends that there will be times when one person is more desirous or needful of certain activities than the other. I believe it is more typical than atypical. It's going to happen and it sucks. Some slaves don't get played with for months or years. That sucks. I'm incredibly fortunate, I know it and don't take it for granted. Except when I'm in the throws of crack addict level desire I don't feel fortunate. I feel miserable.
Being a slave is stupid. And I say that even when I can't do anything or imagine anything (for myself) other than being a slave. The desires lead me to behave in ways that I am ashamed to admit. They drive me to hate myself and everything around me. It's not fair to the other people, so 99 times out of 100 I curb myself and act like a normal person. Then the one time I don't curb myself, I hate myself and swear never to desire pain again. Pain is stupid. Wanting pain is stupid. Being a slave is stupid. When they don't go together it is doubly stupid.