Time to talk.

You approach Jenna as she drinks the water. "So..."
Her face becomes serious. "Now? I don't know baby....I'm drunk..."
"Maybe that's a good thing." You take her hand. "I'm going to need you honest if we're going to talk this through."
"I guesss..." she doesn't seem thrilled with the idea. "Should we talk upstairs?"
"Let's go outside. Fresh air, and no chance of eavesdroppers."
You lead her out to the poolside, grabbing a beer from the summer bar. You could stand to be a little lubricated yourself. You sit down with your feet dangling in the shallow end, and Jenna does the same, trailing her beautiful legs in the water. You marvel once more at her beauty, her amazing body that scarcely noticed that she had given birth to two children.
"Where do we start..." Jenna asks.
"I'll start with a blunt question." You look into the water. "Do you want to go? I'm not asking to be mean. If you aren't happy with me anymore, I want you to tell me. Do you want out?"
"What?" she sounds incredulous. "Why would I?"
"I got you pregnant in high school. You never got to do the things you really wanted." Neither had you, if you admit it to yourself. Your dreams of playing pro ball, as slim as the chances were, had been dashed when you skipped the draft and college to take care of her. "It's understandable if, now that the kids are grown, you realize it was all for them."
"James..." her hand finds yours.
"Like I said, you can tell me."
"No... never..." she sniffles, but maintains her composure. "I mean, I'd be lying if I said I never think about what might have been..." you glance over, and see that she's staring into the water, kicking her feet slowly. "But, no! I love you!" She looks at you. "I've always loved you. I still love you."
You sigh, and take a big swig of beer. "That's good to know, Jen. So... is it..." you swallow hard. "Is it because of my... problem?" Your inability to finish consistently during sex has been a regular thing for a couple of years now.
"No, baby." She squeezes your hand harder. "Sure, sometimes I take it personally...like you don't think I'm sexy anymore, but I know that it's not true. My mistake...it had nothing to do with that."
"So... why?" You look at her, trying to keep the hurt off your face. "Why?"
She stares into the water for a long time. "I...I've been trying to figure that out all day. I love you, you keep me satisfied, and you're adventurous enough to keep things fresh..." Your sex life is fairly vanilla, you think.
"So... did you figure it out?"