Ok true story time…
When I lived in Manhattan. MANY years ago and going to school.
Me and my two friends were bar hopping and were a bit toasted.
A homeless women saw how silly we were and commented on our “fun” behavior. We said come hang out with us.
She said ok. We went back to my friends apartment, had some more drinks.
By the way… She was not that bad looking, around 30ish.
It was a rainy night and we offered her a place to sleep, take a shower and have something to eat.
There was no discussion of sex. But she did let us watch her shower. Did not thrill me much. Her body scared up from multiple puncture wounds.
She had survived many a stabbing.
Then she went into the spare room to sleep and with few words had no problem with any of us coming in her room.
My one friend had sex with her, the other took nude picture of her. Would not admit to doing anything else, I believe he did do more.
I went in and talked to her. Seriously. Asked her about herself and what got her to where she was. It was a sad story. :-(
Then I let her sleep.
She woke up and was heading out. I was heading home and offered to walk with her. I find people interesting.
There came a point where we had to go our separate ways.
I will never forget this person. It was raining, it was evening, New York has that yellowish hue to it. I looked back. Seeing her in the doorway, seeing that loss of life really affected me.
I looked away then looked back again. She was gone. Like she was never there.
To answer the question. If anything, it is a selfish act. Even if the person says, I will fuck you for food. Just give them food. Save the sex for another time and person.
If that person was “crazy” enough to not take the food unless returning the favor. I think there are plenty of things you can have them do, then stealing what little dignity they might still have.