Weekend TV watch

Who will win a coveted surfboard? WWE superstar and West Newbury native John Cena and Victoria Justice host “Teen Choice 2016” (Sunday at 8 p.m. on WFXT, Ch. 25). Flo Rida, Charlie Puth, Jennifer Garner and Sudbury’s own Chris Evans are among the celebs scheduled to appear live.

First lady Michelle Obama drops in on “All in With Cam

Newton” (tonight at 8 on Nickelodeon) to inspire one girl to chase her dream of one day becoming president. “Murder Made Me Famous”

(tomorrow at 9 p.m. on Reelz) revisits the evidence against Steven Avery, the recent focus of Netflix’s docuseries “Making a Murderer.” Avery was erroneously convicted and served 18 years for rape and was later convicted of killing a photographer in a controversial case.

In the second-season premiere of the unscripted

“Boston EMS” (tomorrow at 10 p.m. on WCVB, Ch. 5), paramedics fear a stabbing victim could be wired to explode like a human bomb.

Country music rules on AXS TV on Sunday (starting at 10 a.m.). The channel presents a marathon of concerts starring Willie Nelson, Merle Haggard, Shania Twain, Martina McBride, George Jones and more.

Dr. Ruth Westheimer is still talking about, what else, sex. On the premiere of “Original Sin: Sex — Sex Scandals” (Sunday at 9 p.m. on National Geographic Channel), she and such “experts” as Andy Cohen, Ann Coulter and Margaret Cho will consider our obsession with sex scandals and the circumstances that prompt some public figures to risk everything.