The tour of the lower deck.

"Oh my God!" the twins squealed synchronously when we showed them the spacious master stateroom with its queen size bed.

"No wonder it's so expensive to charter this boat!" Haley exclaimed as she watched her sister leap onto the bed.

"There are more beds down here," I mentioned, pointing back to the hall.

"Really?" Emily gasped, jumping to her feet.

We showed the girls the two berth beds on the starboard side and then the VIP stateroom with its own queen size bed.

"People do more than fish on the boat?" Haley asked innocently as she sat down on the bed.

"Yeah, people charter it for private parties," Bill replied with a smirk. "We're probably going to charter it later with our wives and friends."

"How many friends?" Emily wondered, sitting down on the bed next to her sister.

"Four girls," I replied.

"Your wives' girlfriends?" Emily pressed with a raised eyebrow.

"Not exactly," I answered, "we met them at Sybaris."

"Sybaris?" Emily sputtered.

"The swingers resort?" Haley gasped.

"Yeah, we have a big private cabin there!" Bill gloated.

"So your wives are okay with you having sex with other women?" Emily asked curiously, biting her lower lip when she checked out the big bulges in our shorts.

Bill and I looked at each other and we both knew where the line of questions were going.

"Yeah," Bill grinned proudly.

"Do your wives have sex with other men?" Haley wondered, glancing at her sister.

"Other than Bill and me swapping wives? No," I answered. "That's because I'm trying to get Bill's wife pregnant."

"What?!" the girls exclaimed at the revelation.

"Yeah, my sperm count is too low, " Bill shrugged, having long accepted the fact. "I can't get either of you girls pregnant even if I tried!"

"Oh, really?" the twins hummed, looking at each other.

Bill grinned at me -- he knew his infertility had its bonuses.

"So if the four of us got to know each other better on this trip..." Emily began.

"...perhaps you could invite us to your boat party?" Haley continued, sliding off her top's spaghetti straps.

"...and let us stay at your private cabin?" Emily purred, untying her pink floral bikini top.

Bill and I gawked the blondes' large tits, not as big or perfectly shaped as our wives' breasts but we weren't picky nor complaining.