When you feel like you and your dance partner have been moving together really well and there's a certain chemistry between you two, experiment with a little bit of neutral body-to-body action. Try a hip-to-hip move that glides your hips together up and down, even moving up each other's legs to return to the hip.
If this action seems mutually okay, you can turn your backs to each other and start grinding with some booty action. Again, it's not so much a bump as it is a slow grind of your body part against your partner's. Think of your body waxing the other body like it's a gorgeous Ferrari.
When you both are still dancing and everyone seems like they're onboard with whatever is going to happen, grinding can really get hot and bothered. Pelvises can be ground together or a booty into a pelvis. egs can be lifted by one partner to make the grind just ever so much closer.
Bring things into check with what level you are familiar with your partner and thinking about what you're willing to do in public. The dance floor is a place where you can be erotic and intimate all kinds of thoughts and suggestions. However, it's not the place to act out sexual performances that are better left to private places.