Matt and Foggy cuddling on the couch some time, and after a while Foggy starts to feel the need to pee (or poop or both, honestly, up to you). Matt asks him to stay a bit longer so that he can explore these signs Foggy's body is giving off. Maybe he rubs his lower belly, where it's full. They both enjoy this sensually and emotionally, until Foggy really has to get up and visit the bathroom. Could involve sexytimes, if you want.
No begging, please