It could be said to be analogous. But you also have to take into account the Brehon Law about marriage that existed during the time the Tain is supposed to take place. Mebh is a queen, and higher in status than her husband Ailill, therefore she had the ability to do what she wished. If Ailill wanted to complain, he would have had to drag her before a Court, composed of judges called Brehons, hence the name we give the Law that existed. He might have won recompense for her waywardness, or he might have had to pay her because her higher rank gave her the right to do what she wanted.