Gentlemanly a. : Of, pertaining to, resembling, or becoming, a gentleman; well-behaved; courteous; polite.

Example:
How do you say in a classy, Gentlemanly way to a girl that you want to bone her?

Taxonomy
Merriam-Webster Online Dictionary, Dictionary, webster, tle, Word Games, Webster Online Dictionary with audio pronunciations, thesaurus, glossary, english, language, ESL, ly, adjective, 15th century, characteristic, character, ness, Unabridged Dictionary.

Defination from the web:
gentlemanly from the Merriam-Webster Online Dictionary with audio pronunciations, thesaurus, Word of the Day, and word games. ... Learn more about "gentlemanly" Learn more about "gentlemanly" and related topics at Britannica.com. Pronunciation Symbols. Share this entry: ...