Good for both of you.

You start out fucking her hard and fast, which she seems to enjoy.

After a couple of minutes, she tells you other ways that you can fuck her...

You do her doggystyle, eventually nailing the pace that she prefers.

She tells you what she likes and doesn't like, which makes things work well.

You pull her hair a little bit and give her a light spank or two, but nothing that will leave a lasting mark.

The naughty Aunt teaches other things as well...
For instance, some ladies like to ride you, which helps you save your stamina for later.

In between changing positions, she shows you how girls/ladies can play innocent and cute when they want to.

How does the woman who was fingering herself in front of you, her Sister and her Nieces less than an hour ago now seem so innocent and shy?

You two keep up the fun for the next ten minutes or so before Eva climbs on top of you facing your direction.
She looms over you sexily as she makes you cum in her pussy (since she has an IUD) ...

You both recover and she congratulates you on your good performance.
You tell her that you'll do even better next time.
She agrees, adding an incentive for you.

"I want you to enjoy the others too. If I hear that you pleasured them well, then you can take my ass next time," she says.

You immediately get hard, which makes her smile.