1. You can barely remember what an orgasm feels like. - This is self explanatory, no orgasms means you aren't having good sex and your partner isn't doing their job to ensure you're enjoying it as much as they are.
2. The amount of times you go down on him outnumber the amount of times he goes down on you. - Your partner should want to please you as much as they like to be pleased. This is just the basics of being intimate with someone.
3. Spontaneous sex doesn't happen. - If you have to plan or have a routine then you're in a rut. Honestly, random shower sex or breakfast sex or whatever the flying fuck kind of sex you feel like having is the sign of a healthy relationship. Do not settle for boring!
4. You find your mind wandering to things you need to do or someone else during the act. - If you're mind can even work right during sex you are so settling and your partner needs a kick. There really isn't any way to justify bad sex. Everyone deserves to be a mindless ball of awesome feelings when they are being intimate with their partner, simple.