Request from me question?

Hi, not sure this is a stupid question or not, but someone had asked me to write their xhamster username on my body. I'm willing to please, but am curious as to if this is some sort of scam? Or ploy?

Can they use that picture/video of my body with their name written on me as sort of a watermark for them? Or some sort of.. I'm not sure how to describe it.

I'm just worried the picture/video with their name could be used maliciously somehow.. any thoughts? Or has anyone had this happen, did the request and have been fine?