What makes a sizzling half-naked Drake, 28, selfie even sexier? Our other favorite hottie, Justin Bieber, 21, commenting on it, duh! The pop star complimented the “Best I Ever Had” rapper’s ripped torso on Instagram with a very flattering message. Now, a source tells HollywoodLife.com EXCLUSIVELY why the Biebs had no problem expressing his sheer admiration for Drake’s shredded bod!