Me and friend were buddies from higher secondary and stayed that way into collg, but after the first yr HS me and him kindoff drifted apart, him being a flirt and kindoff started connecting with lots of women(even physically), me more of a straight forward guy and never really understood it.Often seen him flirt with our female college lecturers and is popular among them(I used to wonder how older late 20s ladies blush) in front of a 22 yr old, just because he jokes around them.I used to wonder how it happens.To give you a backdrop, hes this gatecrashing type, never stays at his home, dad abroad, is like 6.4 towering slim, odd looking guy, flirty and kindoff not scared to deal with women, but same time comes out with good grades and stuff.So, I kindoff resented him, because we were two different type of people.Being a friend, hes like friend of my family also, comes around often.Me, him and my younger sis end up watching tv together and he always calls her "sis" and you dont assume anything is out of place so you are like naive.It starts off one day when he asks her, hey sis, can you see me as your "own" bro and she says..i,m your bros friend,lol and then hes like" only a friend, not your bro"?she resents and says, you are my bro also and then looks at me( as if in a guilty way).I dont know something made me uncomfy, maybe having a 6.4 guy who takes up a lot of space, asking your pretty sis to see him as her own bro(its like something is odd), but I couldnt place it why I was feeling odd.By now, she literally started seeing her as a bro(just like shed see me).It kindoff pissed me off once when i went to the fridge and came back, he was sitting next to her watching tv and his hand was on her shoulder(basically on her bra strap) the one that shows out when you have a sleevles on.I was soo pissed, but he dint take his hand of and she kept on watching tv. So, its like hes become a literal brother of the family and more than I would like.How do I avoid him now?