Just a caution to be careful with use of the term soft-swinging as well. Most people tend to consider soft-swinging to include everything but sex. Therefore most people think of soft-swinging to include swapped oral sex, kissing, touching and potentially girl/girl play. It's an ill defined term as different people have different ideas of what it means, so be careful with use of it and make sure that you are clear and up front with anyone you talk to
Have fun!