Yet again, Trump likes to confess, openly and in public, to illegal activities.
On Friday, Trump threatened Comey saying that Comey had better hope that there were no tapes.
For sure, he has threatened Comey via electronic message, which would fall foul of the harassment law.
If there were tapes, then Trump is required, by law, to preserve them, and hand them over to congress for investigation when subpoenaed. If he says no, he's guilty of contempt. If he says he doesn't have them, and later does, he's guilty of perjury.
Pretty much the only way he can get out of this one is 1) hope Comey doesn't sue for the threat and 2) admit that there aren't tapes (or just be done with it and hand the tapes over to Congress).
Bottom line, we've all got better things to be doing than watching Trump Circus.