What it means
A sensitive, arty young man who leans hard into being emotional and deep, all indie playlists, poetry and late-night feelings talk. Used affectionately for a genuinely gentle guy, or with a smirk for the type who performs sensitivity to seem more interesting than he is.
Usage examples
"He made me a playlist of sad songs on the second date, total soft boy."
"Behind the soft boy poetry he was just dodging a straight answer."
"He turned up in a beanie with a battered poetry book and started talking about healing, proper soft boy energy."
"I thought he was sweet, then every text turned into a sad little monologue, man's doing soft boy theatre now."
Where it comes from
Built from plain English soft plus boy, this label took off online in the late 2010s for a certain type of young guy with a tender, artsy, emotionally open image. It grew through meme culture, indie aesthetics, dating chat, and a bit of side-eye about whether the softness was real or a performance.