Strong drink is a mocker, it’s folly, it leads you into temptation by clouding your better judgment. Drunkenness is thus condemned, but drinking wine, in moderation, is not. So, the sinfulness of the two behaviors is not really comparable, since there is no acceptable level of moderation in having sexual relations with your own gender. The only acceptable behavior for an individual stricken with such a propensity to sin would be abstinence, total abstinence and repentance.
But sex within the context of marriage is fine. As with the alcohol, as long as it's within certain parameters, it's not a problem.
So looking at the two comparably, sex outside marriage of any kind would be more akin to *strong drink*.