Ads don't reveal targeting criteria, the visible content of the ad doesn't indicate the user's private profile, it just means an advertiser chose to target them

Ads don't reveal targeting criteria, the visible content of the ad doesn't indicate the user's private profile, it just means an advertiser chose to target them. No one treats the ads you're shown as credible & accurate determinants of anything, let alone sexuality. It might show up in the "ad preferences" page if someone glances over your shoulder while you're looking at it, but generally people glancing over your shoulder to view private information isn't a Facebook privacy problem, it's a people-glancing-over-your-shoulder privacy problem. It turns out that even the most private & secure systems will leak information when you open it and let people see it over your shoulder. It's like saying your web browser puts you in danger if someone glances over your shoulder to see the gay porn you're watching on it.