How to dump a practice partner?

if you can afford it, i'd say try the pro-am. much more conducive to your time constraints and schedule. you choose who you want and have no drama.

You can work on both Smooth and Standard with your Smooth partner. Need both to have good Smooth.

I agree with the others...do both with your smooth partner and focus on being a good partner to her.

Thanks for the advice, everyone.
Since my Standard partner does only Standard and my Smooth partner has a better Standard partner than me, I guess I'll just stop competing Standard for now and focus my practice time on Smooth. That way at least one partner will be happy and stick around I wish I could just find a few more hours to practice Standard but my schedule and my partner's schedule don't match very well to make that possible. Maybe one day a partner will come along, who also works the graveyard shift and we'll have similar practice times.

Any advice on my follow up question from my original post? I should have enough time to take one lesson with a pro per week and practice on my own just to improve gradually, without that interfering with Smooth.

It doesn't matter that you're staying on to take lessons with your partner's teacher. The teacher is a professional and will treat you as such regardless of the partnering issues.

I have to add that I have a similar working situation as you as I am working swing shift now so my schedule and regular folks schedule are exactly opposites. My amateur partner left me and I went to Pro/am to continue my training.