If I understand your question right... my views are, first of all, that scripture doesn't condemn same sex sexual relations in the context of a committed relationship, but rather condemns sexual use by heterosexuals of males as a degraded substitute for women. Secondly, the traditional European age of possible marriage, to be used in exceptional cases where warranted, was 13. (See "Romeo and Juliet," where she was 13). This is the same as the traditional age of the Jewish bar mitzvah, where celebrants say "today I have become a man" and would indeed become theoretically eligible for marriage. It would be very hard to argue that this was scripturally wrong, even though wisdom usually suggests that marriage take place a few years later.

For a committed relationship, parents' permission should be had for those under parental authority. My own view is that because of the possible social power imbalance between younger and older, any legal marital relations with anyone 16 or under should be strictly initiated by the younger partner, who should be questioned to be sure he is aware of what he is doing. Certainly any sexual contact should be the spontaneous, original suggestion of the younger person, not the older. Regardless of the legal situation (e.g. in countries where the age of consent is 13 or 14) people more than three or four years older than a teen should not suggest sexual contact. There is a chance that even an ordinary suggestion could be perceived to have an element of intimidation or undue suasion that could lead to something being done semi-willingly and then followed up by disgust and revulsion. However, if a teen clear-headedly and seriously believes an older person to be the love of their life and wants to engage in a full relationship, then I don't believe Christianity stands against it. I say that knowing that teens are notoriously changeable, because I do know some long lasting marriages where the couples committed to each other at around ages 12 or 13. It is quite possible to find the love of your life at that moment.

Laws that deviate from this, these days, mostly stem from a socialist feminist power analysis that extrapolates from all the aggressively, mostly parentally sexually abused girls to all relations with persons under 16 -18. Eliminating teen girl prostitution is also a driving force, though forbidding sex to eliminate prostitution is an eccentric strategy at best. This power analysis has been swallowed up into our society's basic Victorian dread about sex as something that makes people lose control (either making them shattered victims or out-of-control ogres) and has fuelled the current round of social hysteria. The root cause of this hysteria, though, is that society has more or less accepted gay relationships, so all of the wild imaginings and revulsions that used to be pinned onto gays had no place to go but onto intergenerational relationships. These reactions satisfy some basic psychological needs, so they are more or less bound to attach to some social group connected with forbidden sex.