The most obvious, of course, is Gideon! I did add a little blurb for Gavin in Gideon's bio. He probably doesn't call him "oops baby" as often anymore, but it's still there in his back pocket if necessary. ;) But he absolutely supports Gavin in his pursuits, and probably goes up to Medieval Times at least once or twice a year in that vein. (But, I mean, it's choreographed, so it's not like it changes, lmao.)
I have two characters that bookend his age- Samuel, who was a year behind him in Aurelius, and Marlene, who was a year ahead of him at Athena. Samuel got more involved with the Dunhaven Ren Faire this past year, if Gavin ended up working there or patronizing the festival. Otherwise, I'd be open to discussing things with either of them!