A freeloader is a confirmed guest. He is the man who is always willing to come to dinner.

Runyon’s line turns a social nuisance into a comic “type,” using the language of polite society (“guest”) to expose a less polite reality: the freeloader’s relationship to hospitality is habitual and one‑sided. Calling him a “confirmed guest” suggests permanence and entitlement—someone who has effectively moved from occasional invitee to fixture—while “always willing to come to dinner” satirizes eagerness that costs the speaker nothing but costs others plenty. The humor depends on understatement and inversion: willingness is framed as a virtue, yet it signals opportunism. More broadly, the quip reflects Runyon’s fondness for sketching urban characters whose charm masks self-interest.