score:18
If the kiss was between unmarried, heterosexual youths the boy would be criminally liable to the girl's father, guardian, or another male family member. "... if a woman was an aggrieved party and owned a right of prosecution, she was to put her claim into the hands of a man." [Byock, "Viking Age Iceland" pp. 317] After all, "giving away a daughter in marriage, a father or the head of a household, sometimes a woman, was investing the family's limited marriage capital in a new kinship alliance...." [Byock pp. 214]
If the kiss was between married adults the man would be liable to the woman's husband like the adultery case in Hallfred's Saga [Byock pp. 121].
The law didn't actually govern all extramarital sex: it is clear from the sagas that concubinage was a national custom. Grรกgas barely mentioned it despite its great detail about cases of seduction [Byock pp. 134].