You focus on the right spots.

You ask her to lie on her belly as you squirt some oil on her back. You massage it in very soft and you can her her moan. You slowly make your way down until you reach her ass, which is completely open except for a thong. You can hear even more moans as you massage her round ass.

When you're done with the legs, she turns around says “Now the front.”

Your cock is completely hard in your pants but you continue. Making your upwards from her legs, you admire her flat belly and massage it, the the underside of her heavy tits. Finally you reach up and knead that enormous rack. Her nipples are already hard and you can see a wet spot on the front of her panties.

After massaging her tits for a while, she puts your hands away-

“Now, how about I give YOU a massage?”, she purrs while looking at the tent in your pants.