The story doesn't end at verse 28.<quoted text>
Read the section. Verse 25 mentions the meat market or shambles; verse 27-28 deals with a dinner and whether or not the food was offered to idols or not. Don't know? Don't ask? Offered to idols? Don't eat. End of story.
1Co 10:29 I do not mean your conscience, but his. For why should my liberty be determined by someone else's conscience?
He does not eat it for the sake of a weaker brothers conscience but he has the liberty to eat it because it does not bother his conscience. If it is wrong to eat at the table of demons it is wrong whether your conscience bothers you or not. The liberty statement here is used for justification by gay Christians especially today because it does not bother their conscience.