A person are who enjoys having sexual relations with both sexes. It refers to both having sexual relations and relationships with both sexes.
Girl: Oh i heard you were thinking of hooking up with Anna
boy: yeah shes hot but i was thinking of calling mike
Girl: OH! you swing both ways.
boy: only for fun plus the sex is good.
boy: dave also swings both ways
Girl: no, way
boy: way!
Achieve two mutually exclusive objectives at the same time, especially in a selfish manner.
Reneé wants to have it both ways—by having her boyfriend to live with her. It involves paying on all her bills (instead of their bills) and pay child support on their daughters.