The worst is when you actively dislike your partner and not only do you have to try to trust him on stage, but you also have to act as if you are in love with him.
My first ever partnering on stage was in the Puss in Boots pas. I was young and fairly uncomfortable with the whole thing. The choreography calls for time to run his hand up my leg while it was extended to the side. It was unpleasant. On the other hand, he didn't drop me.
Nora: that IS the nightmare! Yikes! My oaf only dropped me from a simple lift, so I was not seriously hurt.
I will say this. I always preferred solos to partnering. I guess wasn't that trusting of the guys. In classical ballet, they are mostly props to hold us up. I know contemporary has changed that. In any case, I doubt I am not only dancer who prefers to depend on only herself on stage. Plus, as long as no one made me talk, I loved the spotlight.