Some females have a curiosity to engage in same sex encounters. This usually starts with girl on girl encounters, while the 'straight' guys watch. After some playful time as they get more comfortable with their new found sexual liberty, the females become confident and secure in the expanded relationship and experiment more by reaching out to the males.
In our experience most couples involved in soft swing do usually progress on to 'stronger' adult swapping fun. Once they have tasted the pleasure of having a full swap encounter, they rarely return to such a vanilla encounter.
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