Okay, so according to recent upd8, Terezi was stopped from kissing Tavros because her missing scalemate was back, courtesy of John.
She is wearing her glasses again, because remember she took hem off to corpse smooch Tav.
Originally, Terezi never was able to put back on her glasses until later,
Someone ended up with them.
GAMZEE ended up with them,
He used said eyewear to trick Equius into think he was Terezi right before he was about to murder hin.
Causing Nepeta to attack and then also get killed by Gamzee.
Without Terezi’s glasses, Equius would have never tricked and then killed.
TEREZI JUST SAVED NEPETA’S AND EQUIUS’S LIVES