The Brief: "Seggs" is an intentional misspelling of the word "sex."
DEEP DIVE
People may type or say “seggs” instead of “sex” for a variety of reasons including to circumvent online censorship, to semi-covertly talk about sex, or to be silly. The term is popular across social media, including on TikTok where videos associated with the hashtag #Seggs have been viewed nearly 300 million times.
“Seggsy” is a variation of the term that replaces “sexy.”
https://twitter.com/b7andonnn/status/1363275775307358210