Sexual Inadequacy" is the tenth episode of the sixth season of the American animated television series The Simpsons.
In the episode, Homer and Marge's sex life wanes, so Grampa restores it with a homemade revitalizing tonic.
Harvey recommends couples bathe together, but their faucet breaks because the Simpsons' bathtub cannot accommodate Homer and Marge.
The elixir works, so Homer and Grampa sell Simpson & Son Revitalizing Tonic to the public in a traveling medicine show.
After they bicker, Grampa angrily tells Homer he is the result of an unplanned pregnancy that would not have happened without the tonic, labeling him as an accident who ruined Abe's life.
While their parents are enjoying enhanced sex lives from the tonic, the town's children grow suspicious of their absences during their frequent trysts.
After Lisa sarcastically suggests parents are going to bed early because they are "reverse vampires" who must avoid nightfall, the other children decide the RAND Corporation is conspiring with space aliens to deprive children of dinner by forcing their parents to retire early.
Unwilling to forgive a deeply remorseful Grampa, Homer resolves to be a better father to Bart, Lisa and Maggie.
He sees an old photograph of himself as a child on Christmas morning and is sad that his father was not even present when he met Santa Claus.
[6] Warren Martyn and Adrian Wood, the authors of the book I Can't Believe It's a Bigger and Better Updated Unofficial Simpsons Guide, said it was "an amazing episode, in which Homer actually has an argument with someone, rather than backing down.
Watch the closing scene carefully as Homer returns to his childhood home, because Castellaneta gracefully dances between a tender father-son relationship and flat-out comedy".
[7] Colin Jacobson of DVD Movie Guide said he "didn’t remember this as a very good episode, but it actually turns out to be quite strong.