Wat has happened all of a sudden? wat caused him to change all of a sudden?

so theres tis guy tht likes my best friend. he likes her and me. he asked ma frend if any girls had a facebook. so she said ppl and the girl tht he lieks w/me. and so he makes a facebook and strts chatting with my other friend. he keeps askig hu likes him and stuf. isnt tht soo low or like wat? wts up w. him? he used to b so sweet and gentle and very understanding, now he acts so low and stuf.......