What is 5th base?

There is no widely recognized definition or concept of a "5th base" in sexual or relationship terms. In the traditional baseball metaphor for sexual bases, there are only four bases: first, second, third, and home plate. These bases represent various stages of physical intimacy.

It is possible that the term "5th base" has been used colloquially or humorously to refer to a level of intimacy beyond what is typically described by the four bases. However, without a commonly accepted definition, it is difficult to provide specific information about what "5th base" might entail.

Ultimately, it is important to communicate openly and clearly with a partner about boundaries, desires, and expectations when it comes to physical intimacy, rather than relying on vague or undefined terms like "5th base."