Oooo! Me! I use to do some ballroom. I also teach Jazz, Tap, Ballet, Hip-Hop, Musical Theater, Voice lessons, and much more!
As for them not wanting lessons or you not being able to afford them, maybe they could go to a ballroom dance competition?! Or even go to a theater play. I'm not too sure even with my background with this. I'd say classes. Maybe you could arrange something at your house or their house. Invite all their friends and have a nice dinner party, put on some music and have everyone dance ballroom style. IDK. Just an idea. :)
Good luck!
You can PM me if you need to!