I know one thing from past experience, if you are asked what your plans are for the evening, and if you happen to be going to a disco.. and say "we are going to so and so", you can expect to see that person, waiting for you when you get there!!
Then...when you don't give them the attention they are looking for, they try to make you feel bad by saying" well you invited me here and now you don't want to dance with me, even if you have already danced with them a few times...
Invited?? we simply told them where we were going!! Not to meet us there!!
I doubt that you are giving off the wrong vibe, I've heard crazy things too, like if you dance with someone they expect to have sex with you, or if you wear a short skirt-you are good to go! ridiculous things.
Just be aware of your surroundings, make sure you set the rules early on...no inappropriate touching...no grinding (that's up to you) I've seen tourist girls, barely walking in clubs, stumbling all over the place and Sankies all over them. I have yet to see a drunk Dominican at the disco's.
If you are being groped, it's really easy-NO-Don't touch!! it works, they seem to understand that word all to well.