should I stay or move on??

Me and my boyfriend been together for 5yrs ..The first year of our relationship was perfect we had no issues.Going to our 2nd year I realized he was doing a lot of things behind my back like acting like he was home sleeping and me finding out he was out with his friends.i would find pictures on his phone from a night before with him and girls .i just never understood why he would tell me he wanted to get married and be serious but still wanting to live a life of a single man ??5yrs later now he's still doing the same things I feel like I'm wasting my time with him and he doesn't offer me marriage or nothing all he cares about is hanging out with his single friends or his friends that are married but cheat on there wives ..we hardly have sex if we do it's always me wanting it ..I feel I deserve better but I love him he just doesn't put his all on this relationship it's always been me all he thinks about is his friends like if he has something to prove to them .