The 41-year-old writer-actor has penned a fun piece for the April issue of Esquire magazine to reveal why he sticks to his jeans and boots even in summers.
"A friend once shared with me an idiotic maxim: Regardless of the season, a guy's 'attire should always be winter from the waist down: jeans and boots," Theroux writes.
"Chuckling, I dismissed the quote until it dawned on me that he had just described a hips-down uniform I've slavishly adhered to ever since I stopped wearing training pants and Grip 'n' Gos."
The 'Wanderlust' actor says he is averse to anything that is loose fitting. "Maybe it's my long-standing aversion to almost anything loose fitting. Maybe my loyalty to these jeans and boots isn't so much an endorsement of them as it is an expression of my distaste for anything else."
Theroux, who proposed to Aniston, 44, in August 2012, says he'd rather sweat than wear anything else. "The truth is, I'd feel naked without jeans and boots (a feeling that's amplified when I'm actually naked) but in spite of the shin sweat that pours into my boots every summer, I'll still likely be wearing them long after I've traded in my motorcycle for a Jazzy," he said.