Barty LOVES to act like Reg's lover.
Since they're in different houses (Barty is a Ravenclaw, take this headcanon out of my cold dead hands), most mornings Barty just runs in the hall just to hug Reg while he tries to eat.
It's really funny because Pandora is the one having to take Barty out of bed every single morning. My boy is not a morning person and he HATES coffee so he usually just look like a zombie for most of the morning. That doesn't stop him from making a big dramatic entrance in the Big Hall when he sees Regulus. Reggie is so used to it he doesn't do shit while Barty showers him in kisses and tells him how much he's misses him in a dramstic way (well, okay, maybe he smiles like an idiot cause he actuslly loves when Barty does shit like that. It's really funny and he loves the physical contact).
James, at first, got quite jealous of Barty because he didn't understand the relationship he had with Regulus. Reg just laughed for ten minutes when James said Barty had a crush on him.
"James, my deer" which he loves to say because it's really funny and always cracks up James. "Barty is like a brother. We kiss once when we were 12 and it was horrible because he is like a brother"
"He was your first kiss?"
"Kinda. Don't give it much thought, Barty is just like that. He is a friend"
And ok, maybe discovering Barty was Regulus' first kiss hadn't help with James jealousy, but he only needed a few weeks to understand Barty was just a friend. Even though he was always touching Regulus or giving him hug and kisses, there was no passion in them. Barty was all about friendship.
Evan wasn't as good as James. He was getting angry without even knowing why (he's jealous) and started questioning Barty why doesn't he do the same with him. Barty just smiles and kiss his cheek.
"Still not into lads?" Barty asked, preparing to kiss the other cheek.
"Yes. Why?" Evan frowned, token by surprise.
" No reason" Barty laughed, giving another kiss. This time he put his lips in Evan's jaw, feeling the blond melt under his touch. "Just checking"