Ángel and Margot both would, except that they're currently in a relationship/married (respectively), and thus not on the market.
Carlos has nothing against it in general, but doesn't feel it's for him personally (and he's also married).
Jessie probably *will* sometime after the events of the book, when she feels like dating again.
David is 28, gay, and single. Yes, *of course* he's on Grindr! (Although that's more of a supplement to meeting men in clubs.) 2/2