what's with the Dinklage character?

Not at all.

The previous scene Marley is lower than low, and her friend (being a good friend who knows her real self and her humour) hires Vinnie to basically cheer her up, and take her mind from her sickness, even for a little while.

It is his and her kind of shared humour, to hire an 'unusual' male escort in her darkest moment. It had nothing to do with 'jerking her around'......he was doing what a friend would do to alleviate the sadness for a moment.

But as I recall, she didn't seem amused.