Need advice

Hello everyone, I'm new here and need some advices! I have been dating a girl for six months, and dream of becoming a cuckold. Wanna to find us a guy with whom she will have chemistry and romantic and hardcore sex, of course. My problem is girlfriend says she doesn't want to but like that I get turned on by imagining her during sex with another guy oh. Who had a similar situation? Maybe I'll find a friend here to persuade my girlfriend.
 
Hello everyone, I'm new here and need some advices! I have been dating a girl for six months, and dream of becoming a cuckold. Wanna to find us a guy with whom she will have chemistry and romantic and hardcore sex, of course. My problem is girlfriend says she doesn't want to but like that I get turned on by imagining her during sex with another guy oh. Who had a similar situation? Maybe I'll find a friend here to persuade my girlfriend.
please tell your ages and her bra size