Tennessee is one of the 11 US states where the Age of Consent is 18. (The other 39 are 17 (eight states) or 16 (thirty one states)). Unless there is a “Romeo and Juliet” exemption in TENN for those close in age (and I cannot seem to find any such clause in the TENN statutes yet), these 3 fine young gentlemen should have a lifetime of registries and reporting ahead of them.
Tennessee has one: Tenn. Code § 39-13-506 (2017)