A secret affair during carnival
Carnival is a time to have fun and celebrate your worries away. It may also be a time for a secret love affair or, as the Germans would say, a Techtelmechtel. This funny-sounding word likely comes from the Yiddish tachti, which more or less means "secret." The second part of the word has no special meaning, other than to echo the first part as a rhyme.
A Techtelmechtel historically meant a secret love. This could have been anything from a casual flirt to a secret affair. After carnival however, a Techtelmechtel could be even more secretive, as - come Ash Wednesday - festivities are set aside and life again turns sober.