I have!

Never have I ever fallen off and got it on camera

I have xD

never have I ever been in a relationship.

never, thankfully.

never have i ever used a martingale

I haven't. Never have I ever had/have my own horse

I have

Never have I ever been to a Grand Prix (to spectate)

I haven't

Never have I ever showed english

I have not (Never showed, but ride english)

Never have I ever been stung by a bug

I have, unfortunately

never have i ever jumped more than 18 inches

I have

Never have I ever forgotten a piece of tack at a horse show

I have not. Never have I ever trained a young horse