Alana Church 
His Lusty MILF Librarian [EPUB ebook] 

Every year, Brynn Martin chooses a high-school senior to be her lover during the summer. Michael Kroger is the poor son of a single mother, working and saving for college. But when Michael goes to Brynn's house to return a lost debit card, his world gets turned upside down. Because he's won a night in bed from "His Lusty MILF Librarian!"
~~~~~ PG Excerpt ~~~~~
Brynn covered the pot and bent to place it back in the oven. As she did, she became aware of two things.
First, her robe was riding a little…high on her thighs as she bent over. The warm air of the kitchen flowed in, doing little to cool the carnal heat in her core, which had become more aroused, not less, due to Michael's presence.
Secondly, she confirmed with a quick glance over her shoulder, Michael's eyes were riveted on her. The knuckles on the hand that held his mug were white with strain, but his face was red as a stop sign.
But I don't want him to stop. I want him to start.
But I think it's going to take a little push to get him going.
Not hurrying, Brynn closed the door and pulled off her oven mitts, placing them neatly on the counter. "So, Michael, " she said as she sat back down, making sure she was between him and the door. "Did you like what you saw?"
If anything, his blush grew fiercer. "I don't know what you're talking about."
"Oh, I think you do." Carefully, as if he were a shy animal unused to a friendly gesture, she put a hand on his forearm. The muscles there were hard and tense. "I don't mind. How would we ever get cute little babies if men and women didn't find each other attractive?"
She could barely hear his mutter. "I…I shouldn't be looking at you like that. It's not polite."
"Polite?" She laughed, deep and clear, and Michael's head jerked up in surprise. "Who the heck cares about polite? Polite is for when you're visiting your grandmother, or making sure that everyone gets a cupcake at the birthday party.
"When I have a handsome young man like you in my kitchen, Michael, I don't want him to be polite. I want to know that he finds me attractive.
"So? Do you?"
Brynn saw his lips shape the word, but no sound reached her ears. Keeping her voice warm and kind, she repeated herself. "Do you?"
This time she heard him. "Yes."
Her body tingled with the thrill of triumph. But it was a long way from this reluctant admission to having the young man in her bed. "Well. That wasn't so hard, was it?" Despite her promise to be good, she let her smile widen. "And is it?"
"Is it what?"
"Hard, of course." Her hand slid down Michael's arm. A good arm, young and strong. Her thumb danced over his knuckles. "That's the wonderful thing about high-school men. I get older. But they stay the same age."