Spells like Suggestion and Charm Person have lines in their description that indicate the spell ends if you or your companions do anything harmful or damaging to the creature. For example, Suggestion has the following line:
If you or any of your companions damage the target, the spell ends.
And Charm Person says:
If it fails the saving throw, it is charmed by you until the spell ends or until you or your companions do anything harmful to it.
I've always taken this to mean that when you damage/harm the target the fact that you're directly damaging them causes them to be brought to their senses that they're under the effects of a spell by a hostile creature and so they 'snap out of it' so to speak. Essentially in my mind damaging the target triggers a 'saving throw' with so much advantage that they automatically beat the DC.
As such, my question is this: if the target isn't aware that I'm the one damaging them, does the spell still end?
For example:
As a Sorcerer I cast Suggestion on an enemy and tell them to take off their plate armor, and then while they're in the middle of taking off their armor I use Subtle Spell Metamagic to cast Fire Bolt at the same enemy.
Does my Suggestion spell then end even though there was no verbal or somatic indication that I was the one who cast it at them?
In my mind I don't think it would as long as I can convince the target that the Fire Bolt came from something other than myself and would therefore not trigger the new 'saving throw' with an auto success, but I'm curious to see what other people think about the situation.
P.S. I'm aware it's not actually a saving throw that's triggered I just can't think of a better way to describe it.
Best Answer
The charm effect ends when the spell says it ends.
Generally speaking, spells in D&D 5E do what they say they do. They are meant to be mostly self-explanatory, without needing any hidden rules or further interpretation. The charm person spell is explicit about any conditions that end the charm effect:
According to the written text, it doesn't matter whether the charmed creature realizes who hit it, or even knows that it was harmed. The spell text is clear. If the caster (or a caster's ally) harms the creature, then the spell ends, because that's how the spell's logic is written.
For example, suppose the sorcerer casts charm person on the bugbear, and later casts fire bolt with Subtle Spell to disguise the casting. Yes, maybe the bugbear doesn't realize that the sorcerer cast fire bolt. However, the sorcerer's attack would break the charm effect, and the bugbear would know that the sorcerer had charmed it.