Keep making out

You decide to try to keep her occupied with you so she doesn't realize what a show she's putting on for the others on the beach. As you kiss Kate passionately, your hand trails down south, feeling for the edge of her bikini bottoms with your fingertips. She disengages from your embrace long enough to begin a protest.

"And just what do you think you're doing, mister?" Kate's voice is more playful than you expected, this could work. You struggle to make up a line on the spot. "What? Is it so wrong for a man to want to make his special lady feel good?" It's really cheesy. You probably could've done better than that, but at this moment, most of the blood from your brain has rushed to your erection, which decides that a good way to persuade her would be to press itself against her thigh, which you do.

Kate looks into your eyes as she clearly feels your hardon. "Are you serious? Can't you think of anything else?" You notice her lips barely parting and her enormous breasts heaving as her breathing gets heavier. Mayhaps she doth protest too much...