"Can I see them?"

I ask, trying to look innocent.

Millie understands what I mean instantly, and I can tell she is thinking about it. She takes a few seconds, then she reaches behind her and unties her bikini-top, while looking me in the eyes.

Millie has gotten her bikini untied, but before she lets the strings go she says:

"Do not tell your dad about this."

"I promise." I say, trying to sound calm and collected, but inside my heart is racing. I am about to see my step-mom Millie's big tits!

Millie waits for a second, then releases the strings and her bikini drops down and her big tits come tumbling out from under it. They drop down a little when no longer held back by the bikini, but not very much as they are really firm.

My step-mom's tits are even nicer than I imagined them. They are very big, clearly fake but very high quality fakes, with nice sized brown aereolas and upward pointing brown nipples.

I just sit there and look at them for a while. Millie notices my reaction and it seems to delight her, and then her eyes move quickly to my crotch area, checking to see if I have gotten hard from seeing them. I have tried my best to fold my legs so my boner is not easily visible, but I shift them a bit so that Millie can see it making a bulge in my pants, and I can see a glimmer in her eyes when she notices it.

I know what I want to ask next, but I don't want to push too far and risk angering her.