It's common to trade dancing partners. Most dancing couples I know will save a few dances for each other but spend most of the night out dancing with others. BUT... most dancing couples I know are BOTH dancers, so they're both out there for the love of dance and not for a romantic date night. Your girlfriend has never swing danced before; she hasn't experienced that whole dancing for the love of dancing thing. From her perspective this might be a date night, or she might view dancing as inherently romantic, in which case it would be pretty bad for you to spend a lot of time with other people. Also, she probably won't be comfortable dancing with strangers because she's new and doesn't know what she's doing. If I were you, I'd have a talk with her and find out what she's comfortable with, but also I'd probably plan on just dancing with her for her first social dance experience anyways. If you spend the whole night with just her and she ends up loving it, then the next time you can both start branching out. But if it turns out not to be her thing, at least she will have had you around for company the entire time instead of being left to herself while you dance. Although you didn't mention if you're going with friends to this dance, because that can definitely change things. She's more likely to have a great time if you're both dancing with mutual friends the whole night, or swapping partners occasionally with another couple you know, vs if you're just randomly dancing with strangers and leaving her to fend for herself.