Nothing is ever simple, depending on the spin we put on it. What constitutes sex came up in a discussion at one time, and a friend was quick to give the reply: "Well, that's easy, intercourse!" Suffice to note that another immediately shot back with: "Yeah. Now tell us what constitutes intercourse, wiseass!" And then it was chaos, of course. Regular intercourse, anal intercourse, blowjobs? and what not.
Here at the Zity the concept of what sex is, expands considerably. People engaging in enema play, dildo play, BDSM, you name it. Sex, I think, is the act of engaging in vaginal, anal or oral intercourse, including masturbation by another, in any way, shape or form. I think that is what is understood under the term "sex" in legal context in most countries and in most cultures at this time. An enema with masturbation, administered by a person to someone else, then clearly constitutes sex.
But now we get to the fuzzy part. Activities with sexual overtones or sexual innuendo, no explicit sexual contact or masturbation. What if I help out a sexy neighbour with constipation by volunteering to give her an enema, I get as horny as hell, she gets all moist and dripping and clearly enjoys the procedure but nothing happens beyond that? No "inapproriate" touching, talking or anything else? I would call that a near-miss, or almost-sex. Not quite sex - yet. But what if she (or I) have a spontaneous orgasm, still not brought about by anything "inappropriate"? You have to agree that everything becomes very uncertain. If a jealous partner walks in on this situation, what he/she regards it to be may be very different to your lame excuse! 😁
The point is, what we regard as sex and when "boundaries are crossed" becomes a matter of opinion, depending on not only the situation itself, but also on the mindset and mood of the observer. There is really no hard and fast rule.