His dick won't work, but do his hands or his lips?  I mean it's not like men can't enjoy kissing, cuddling, cunnilingus, etc.  If he wants to do stuff he can do it, regardless of any medical issue his penis may be having.  The failed boner sounds more like an organically arising excuse.  I imagine him getting the Viagra as part of a half-hearted plan to maybe fake his way through sex and thus avoid actually talking about this stuff with you...  but who knows.  Can't read the dude's mind over the Internet.  You sound hot to me though.  This makes it easy for me to assume he is hiding something, running away from something, or what-have-you.  But who knows. Maybe he no longer truly finds you attractive, but is extremely reluctant to tell you?  it cannot just be coincidence that we have not had sex since becoming normal weight.  Well, many things are possible.  Coincidences are possible.  But yeah it sounds very suspicious.