Your intention doesn't make it any less blackmail; it changes nothing.

[And you thought he was looking at you coldly before? It's worse now. Because you just implied that his friend should become a prostitute.] You had better not be seriously suggesting that.

[He could have said something quite a bit more cruel, here. Like if that's such a good way to make money, she can go do it herself. But there are lines he doesn't cross. Telling a girl to whore herself out is one of them.]