TikTok hopes to spread Bieber fever on Valentine’s Day. Justin Bieber will perform the first-ever full-length single-artist concert to be broadcast live on TikTok live from Drew House on February 14 at 6 p.m. PT / 9 p.m. ET, with a rehearsal scheduled for February 15 at 11 a.m. PT / 2 p.m. ET . The show will mark Bieber’s …