I need HELP!!!?

im with this wonderful guy.. He makes me feel great and loved and wonderful but im very confused on what i should do.... see about a week before we meet i hooked up with one of his friends... and after meeting my boyfriend at a party we clicked and i love him. But now comes the hard part he doesnt know that me and his freind hooked up before i meet him and im scared taht his friend might tell him.. see lately my boyfriend has been bringin ,me around his friends and it gets hard cuzh his friend he gives me these looks and i feel bad cuz on saturday he told me that it was cool that he just thought that it would be him in my bf shoes.. and i just stayed quiet... i didnt know what to say .. should i talk to him and tell my boyfriend the truth? should i talk to his friend??? i dont knw im just lost i dont wnat to lose my boyfriend