Wanna REALLY know about somebody? Talk to their roommate ...
Which is why we spoke with the guy who lived with Carson Wentz -- the QB's ex-college teammate Jedre Cyr ... who says Carson is so squeaky clean, he'd let him date his sister!
Wentz roomed up with Cyr (fullback) during their time on the football team at North Dakota State -- and was raving about how Wentz might be the biggest choir boy he's ever met.
"As in the words of our offensive coordinator, he's not the kind of guy you're going to see out at the bar having a drink and slapping a girl's ass ... he's not Johnny Manziel."