My best mate trying to bed my sister: Is it real or surreal ?

Me and my best mate were pretty close in senior high, but he changed a bit, turned out to be a big jock type, smooth talking and went on moving on from one girl to the other, used to flirt up our teachers, who would respond in Kind and was having many gfs.He was like 6.4 , not bad looking and had noo issues chatting women up, while I on the other hand was a one girl type, crushed on one girl all throught and never acted on it.It was like suddenly he outgrew me and I was kindoff feeling resentful about it.He was also not an open guy, had his own private life, once he had an affair with his neighbour(who was like 23 or 24 then or older to us) and she got knocked up(rumor is/not confirmed but people say), so there were some issues and he dint come to write exams for like 6 months.When he returned, i asked him, what had happen and he wasnt willing to share.