I thought the same thing. It looks like someone else kissed him without him knowing
i was thinking he kisses him and filmed it and outed him or maybe had others watch
oh, that might be it! since they were in a classroom. and it makes a lot of sense because after Cirrus kissed him he said something like "people are staring, they look at me weird" and he looked absolutely terrified. all that fear and anxiety led him to puke too. he was definitely outed once, and now twice because of Cirrus. poor Skylar, he needs a hug :(
holy shit- so okay this is just my guess but maybe in the past our Skylar liked a guy and this guy agreed to make out with him if he wore a blindfold but instead of doing as he promised the scumbag made him kiss some other rando (maybe he was forced by that bully, or maybe he had a crush on Skylar already), and that scarred Skylar forever? So maybe hes found kissing repulsive ever since and with Cirrus forcing him into a kiss that wound obviously opened up and those unpleasant memories came back at once... man if this is somewhere near accurate then I feel so sorry for him