Green’s Dictionary of Slang

(orig. US) self-aggrandizement, boastfulness, egocentricity.

1968		N. von Hoffman We are the People Our Parents Warned Us Against 109: All these people away on power trips and ego trips.
1970		Meyer & Ebert Beyond Valley of the Dolls [film script] I dig, man.You’re on an ego trip.
1976		P. Theroux Family Arsenal 124: There’s no ego-trip involved – they’re not interested in stars and personalities.
1985		‘Thommo’ Dict. Aus. Swearing & Sex Sayings 41: EGO TRIP — When one is in need of attention or admiration and is very self concious [sic] of their actions or mannerisms while feeling in competition with others.
1988		Ice-T ‘Heartbeat’ 🎵 I’m on a hype trip, this ain’t no ego trip.
1990		R.G. Barratt ‘I’m not a Racist’ in What Do You Reckon (1997) [ebook] [P]eople like Carlton and Singleton on these self-righteous, holier-than-thou, ego-trips.
1993		I. Welsh Trainspotting 180: These things [i.e. pit bulls] are just killers. It’s a big ego-trip for these daft cunts tae own them.
2002		‘Touré’ Portable Promised Land (ms.) 157: We Words (My Favorite Things) [...] Quiet storm. Ego trip. Playa hate.