Sorry, I meant to post this sooner but I've had a busy couple of days. Anyway, a rough translation of what's going on is this:
The Manga is called "Ultra-Busty Young Girl Rikako" (Chounyu shojo Rikako-chan). In the first part, this girl describes how her tits are really big. She meets a (potential?) boy friend and asks him if he really, really likes big boobs. He assures her that he does and starts to fondle hers. At that point, she says "oh, when girls boobs get aroused, they swell up", and hers do so, popping her buttons and jacket off. This is the actual BE scene, but they're mostly pretty big to start with.
Right after this scene, the boy suddenly finds himself in a restaurant with a slightly smaller, but still huge version of the same girl as his waitress. He was apparently daydreaming the earlier scene, but he's disoriented and confused. The girl tries to take his order and he tells her he's undecided. The girl goes to the bartender in the restaurant, who openly plays with her boobs. She goes back to the boy's table and he orders coffee.
Next she goes to a middle-aged guy's table and he orders milk. She explains that she'll provide this herself and lets the guy suck it from her boobs.
Needless to say, the boy decides he'd rather have milk than coffee, so he orders it too. The girl tells him to drink his coffee cream. He is disappointed.
That's the plot.