What does the Bible have to say about an adulterer? Because that is all that really counts, because it is God's Word for us today, not some prophecy by who knows who!
"You shall not commit adultery." Ex. 20:14
"He who commits adultery lacks sense; he who does it destroys himself." Prob. 6:32
"But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart." Matt 5:28
"Let marriage be held in honor among all, and let the marriage bed be undefiled, for God will judge the sexually immoral and adulterous." Hebrews 13:4
"And I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery.” Matt 19:9
"Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body." 1 Cor. 6:18
"For you may be sure of this, that everyone who is sexually immoral or impure, or who is covetous (that is, an idolater), has no inheritance in the kingdom of Christ and God." Eph. 5:5
There are a lot more verses. God really hates the adultery, and you have not said whether he is repented. However, keeping track of Viagra or Cilias pills really doesn't sound like a good way to know if he is cheating. You need to have a talk with him, and tell him to leave. I doubt at this point he is going to stop. Why should he, as Ladybug said, he seems to be having his cake and eating it too?
Do stop sleeping with him or even kissing him. And do get some counselling.
God bless!