PLEASE HELP! My Boyfriend Wants Me To Have Se X With His Father Before We Can Get Married What Should I Do

I need your help urgently. I am supposed to be introducing my boyfriend to my parents. But the problem is that my boyfriend says his culture dictates that his father first “tastes” me to  know exactly where his cows are going and if I’m valuable. My boyfriend is okay with it because its his culture and he wants me get married to him but I have a big problem with it, I can’t run out because I love this man dearly. What should I do?