Should I stay or leave him

Mai 4 saal se ek ladke ke piche thi. usne mujhe hope dilaya ki hum relationship me aayenge but at the end he started acting different. we did everything. but kl mujhe pta chl vo apne ek bahen jaisi dost ke sang hickey li aur jo bhi hua mujhe nhi pta.

usne merese kaha dost rehne ko ab. aur aaj milne aa rha hai. cuz he said to clear things.