Wow! thanks the video, didn't know it existed. One more question: how do u know he is open about his sexuality? Tried googling to see if he's said in any other interview but nada.
Well, other than the video (you're welcome by te way), he often jokes about boys he could be going out with, when he's asked about a potential boyfriend he doesn't elude it or turn the question down but instead cracks another joke, he hangs out with gays in Le Marais (Paris gay district) or during Pride... but we can mostly only see that in his stories, so they're not there long (there's at least that Instagram post, which has been posted one and a half year ago --- it's also a joke but he didn't put himself in that situation with a woman, but well, these are all just examples).
Oh yeah, also, he sometimes shares e-mails and text messages he receives where he is sexually harassed by men who take advantage of him doing personal coaching in his apartment or posting sexy pictures on his Instagram account thinking it means it's okay for them to objectify him, ask for sex, act horny etc. ; he makes a joke out of this type of situation (again), but if he weren't gay I really think it would be worse, like he wouldn't react the same way