She let's him pay for her.

You're lucky that Duncan had turned to look at her otherwise he'd have seen you gawp and go slightly red at both these events, his comment and her timely arrival. You quickly straighten yourself up and say hello to Baylie and invite her to sit by Duncan.
She obliges quickly, almost as if she's in a rush. But she's refusing to look at you, not even in the eye but at any part of you. Her face seems red but it could just be because of the exercise she's presumably just done. Duncan doesn't seem to notice though. Without waiting you decide to get this awkward encounter over with.
"So Baylie, do you give permission for Duncan to pay off your remaining debt with me?"
"Yes yes," she quickly gets out whilst looking at her feet. You can't help but notice how her leggings and vest hug her toned slim body. You shake your head slightly before turning to Duncan.
"Right, if you could just fill out this form so I have your details and then you can pay straight away." you say and he nods and after you've handed over the paper he quickly fills it all our. In under 10 minutes he's made the payment and you thank him. You then turn to Baylie and thank her as well for keeping up her deadline and paying. Just as you finish this and are about to say bye to them both she looks straight into your eyes. The lust in her blue eyes is so obvious that you feel your cheeks redden a little as hers go almost bright crimson. You both don't say anything for what seems like ages as you seem to both be undressing each other.
"Right, we'll be off, thank you." Duncan says as he stands seemingly oblivious to you and Baylie's look. With both of you only having just turn your attention to him as he spoke.
Just as they're about to leave you suddenly blurt out "Um, actually there's a few more things I need Baylie to fill out as well."
"Oh," she replies her face going back to the bright red it had just been, before turning to Duncan as if unsure what to do.
"Oh yes, certainly," he replies after looking at Baylie.
Just as you bring up a few documents from a draw, just information ones that Baylie has already filled out, you suddenly say "You don't need to stay Duncan though, now. I don't need you here anymore." As you say this Baylie also turns to look at him a mixed expression on her face.