Is he cheating or am I just overreacting?

My boyfriend of two years has started hanging around his cousins and these guys are whores they sleep around and my boyfriend admitted he would also sleep around with girls I guess it was a group thing even in a relation ship and engaged to his ex he slept around they encouraged him on top of him and his ex having problems. Skipping thru that summer has come and last night one of the whore codons stayed the night hes cool but I dont like my guy around him because I know what hes about he wants to sex anything walking so tonight right now my guy is gone and out with the whore we had a small argument when he, was getting ready to leave because they got dressed up real nice and claim they didnt know what they were doing tonight so they are gone is been 3 hours I xalled my guy twice no answer our call back the whores phone is dead our turned off and I'm feeling very uneasy and pissed off ......a few extra tips a week ago I found two condomsa one a magnum the other was his sisters but I feel he took it from her. I ask to throw them put because we dont use them out to let me give them back to his sister who lives in tje same house with us he said no to both so when he got out I ruined bothes then yesterday I was doing laundry he was emptying his pockets and he pulled a condom out amd xlaimed he did it to pissed me off he likes when I get mad but I dont find an ything like that funny. Most of tje time hes with me but I do bo work 8pm to 3 in which he usually sleeps on until I'm not sure what to think please give me your advice guys