This type of swinging doesn't involve any real sexual contact. Is usually limited to dancing, flirting, kissing, and light petting with people outside of their own relationship with neither partner getting jealous.
"I can't believe Dan isn't mad that Julie sat on my lap and kissed me!"
"Ahh don't worry about it, dude. They're softcore swingers, they both do this all the time. Just don't expect it to go any farther"