When you put it that way it seems silly to consider the technicality of sin.
If you discover your motive is to selfishly seek your own physical gratification, instead refocus on what is pure (Phi 4:8).
The Bible uses words like adultery, fornication, lust, and purity, all words that have very clear meanings.
Yet many Christian singles, teens, and even parents remain confused.
But the problem with most views of boundaries is that purity itself becomes conceived of as a list, rather than as a kind of relationship with Christ, community, and a romantic other.