出典:Wiktionary
The verb is from The Terrible Sea Lion, a 2014 strip in the webcomic Wondermark, in which a character expresses a dislike of sea lions and a passing sea lion repeatedly, intrusively asks the character to explain.[1][2][3]
sealion (三人称単数 現在形 sealions, 現在分詞 sealioning, 過去形および過去分詞形 sealioned)