Cock magic obviously... Why would the school nurse, teacher, stepmum, sister and every other wakung vagina in the fucking city fuck us... lmao
That's easy cause they are cock-hungry sluts !
I mean so far everyone is, but some have higher reasons for not doing it...
Rachel's mom - because she is afraid Rachel will feel hurt (despite her being allowed to fuck around in Beth's party)
Jasmin - Nesrot's girl, and despises Warren and his group
Jaqueline - Main muscle of Nesrot, and was threatened with physical abuse and rape by the Gentlemen gang
Blis - main assassin for the Gentleman gang, and fiercely loyal to Warren
compare that to the examples you listed...
Sarah - from the start kinda has a crush on you, to the point she keeps a diary about wanting to bang you, and has to be convinced its bad by her BFF
Maria - certified nympho stated by multiple different characters, she cant help herself
Nurse - was immediately smitten by your penus, and know hungrily awaits BoN to give her a chance to jump on it
Teacher - always liked you (sexually), and you saving her from rape, tipped the scales in your favor
Everyone else you do favors for to get in good graces, and sexually tease them till the point they just want to get ravaged...