Bootlicking is fairly sfw. As long as they are wearing more than just the boots. Internet only labels something nsfw when there are presenting nipples, genitalia; derogatory and vivid sexual language.
While bootlicking can have a sexual context, it’s less sexual than say toe sucking because it describes an action onto an article of clothing rather than a specific body part.
Kissing is usually considered sfw despite this but ass kissing is different. Bootlicking is still a watered down version of ass kissing, which doesn’t usually have a sexual connotation but is still quite vivid. And while bootlicking is derogatory, usually toward the one licking the boot, you’d find most people who actually enjoy bootlicking to find such descriptions offensive to them.
Besides, without bootlicking at work, then no one would get promotions.
Why yes, I put way too much thought into this but thinking is usually fun for me.
