NEED SEX ADVICE!

S

My boyfriend and i have been together for 6 months. Every single time that we have sex he always finishes very very quickly and i’m talking about 2 minutes sometimes 5 minutes. Why does he finish so quickly? He doesn’t even understand why either lol. He even told me he usually lasts 40 minutes with a girl. Not sure if i believe that one. Does it mean he’s that turned on when we have sex? Like i’m so confused!! Please need some advice!!