Incredibly satisfying self-pleasure. After she leaves, I keep myself busy for a while, until enough time has passed that she is feasibly engaged with him. I'll shower, put clean sheets on our bed, get things ready for her return. Then when enough time has passed that it is possible that she's already begun, I lay in our bed naked, thinking about it. Imagining what might be happening. There comes a point where enough time has passed that it is certain that she has begun, if not already completed round one.
I try to see how close I can get to cumming without losing control. At some point, I'll go ahead and let it happen, in hopes of taking enough of an edge off of it that I can last more than a few minutes (or seconds) when she brings home her cummy pussy to enjoy.