Its when a person that is in a marriage or relationship (boyfriend and girlfriend or same sex) has a intimate relationship with someone other than their spouse/lover that they r in a relationship with and the other partner or spouse knows of it but does not mind/care.
its not a threesome because it is seperate from the serious or not so serious relationship that the person is in .its not cheating because the other person knows about it and does not care.
some ringuls will say they are single to be in a relationship with someone who probably wont date them if they were not single;so they lie and say they are .
i'am ringul(pronounced ringle) ka-el so my husband does not mine if iam romantically involved with you.