Rita is scandalized. She is a campus queen, one of the top students at the school, one of those all others defer to. In fact, she can simply order half the students on the campus to show up to be her breakfast, and her victim will see no alternative to showing up on time and being consumed. She is big stuff. Now she is supposed to be free food for the lowest of the low, mere lab rats who are just the playthings of the researchers? What makes Marilyn think she will stand for such a humiliation?

She already knows. Marilyn would simply ask "Are you a scientist or not?" And when Rita says "Yes", she would continue "Well, there you are."
Much as Rita hates it, she has to agree. A scientist has to use all of her resources as best she can. And that includes the scientist herself. If letting the specimens eat her improves the results, that is her duty. She doesn't have to like it, but she has to do it. With a sigh, she swallows a little data packet that will record her physical reactions to being eaten and digested. Then she turns to Dorothy and offers herself.

Dorothy wants her feet first, a favored way of Rita's, but when she is dining. When she is the food, it is quite a different matter. Now she will have to watch her doom approach instead of watch the other girl watching her.
Dorothy takes her time, licking Rita's feet as she swallows them, and using her hands on Rita's clit immediately, by having Rita bend at waist and knees. To Rita's disgust, she is quick aroused, and climaxes loudly before her knees are out of sight.
Rita had long been of the opinion that bringing a lass to mechanical climax like this was demeaning and controlling her, an opinion Dorothy seems to share. As she moves up Rita's thighs, she continues to send her victim over the top despite Rita's efforts to maintain her control. A really pleasant form of dominance, but still dominance, and Rita can't do much about it.
Once her slit is reached, she can do even less. Dorothy attacks her vitals time after time, until Rita can't even keep track of how many times she has come. Indeed, to where she can't keep track of anything, becoming a mindless toy eager to please her devourer.
Once she realizes Rita is out of it, Dorothy gets down to eating, pausing merely to play with the girl's boobs until she once again sings out with joy. Then her shoulders and head vanish inside and Rita is left to playing with herself as Dorothy sits back as enjoys her food.