I can see where some teens would be a little less inclined to ship Felicity and Roy via that age difference (even I'm like, well, it's not the age difference but the life experience and that's shrinking in Season 2 but it's still there) but Felicity and John are not...even...an age difference.

Though I never shipped Harry with any of his professors, but then I'm more of a peer-peer type shipper.