Throwing a little singles auction is a great idea for a one sex Valentine party.
What exactly do I mean? Well, if you are throwing a party for your girlfriends, also invite a few of your guy friends and ask them to participate in your auction. Vice versa of course, if you are having a party for guys.
It's not that hard. You'll need a few participants and a lot of interesting bidders. Make sure that participants are clear on what's going on and that you have enough single guests that will be interested in biding.
Make up fun stuff that bidders can bid on. Here are a few examples:
Each guy or girl that your guests bid on, first walks pass the room like a model. Then you announce the start of biding and take bids. The highest bid wins! It's as simple as that!
The bidders will have fun, the "prizes" probably too and maybe it will also be a start of a new couple.