Ah, a Nice Guy problem. I think a lot of it depends on whether Jenni truly wants to stay friends with Max. If she doesn't, lots of the above advice is good; she can absolutely feel like she's in the right to cut ties. If she does want to be his friend, I think she should have a very clear talk with him. Tell him that she's not interested in him romantically (here he may try to deny he's into her, that happens someones) and because of that, she's no longer comfortable accepting X Y and Z from him.
If he pulls the 'sad' card and tells her he's just being nice, she should tell him that since he wants to be nice to her, he should respect her wishes. Because at this point *she* is doing *him* a favor by letting him do things for her, not the other way around.
From previous experience, I don't see this ending well, but hopefully Jenni can make it clear as soon as possible. Anytime Max pushes boundaries she can just repeat "I'm not comfortable". That makes it have nothing to do with *his* intentions at all. He will argue his intentions are good, so she should be fine with it, but she can tell him "look, it doesn't matter what you mean by it, even if you aren't hitting on me I am still not comfortable with it".