Third party??? Oh! gosh that would be very hurtful in the part of the original girlfriend or boyfriend.
Hearing about third party, really embarrassed me, know why? it seems like that person is not loyal to his/ her partner.
Why is it that they are still finding another person where in fact they have already someone. It just means that they are not contented, or they don't no longer love the first one that's why they enter with another relationship or rather an affair with another guy, or woman..
I hope that it won't happen to me, if it does.,,,,I don't know what would I do.