You are being asked to play into the contorted (you might even say deluded) way that many obsess about penis size. Inflation runs especially high on apps, where (at least in the gay world) it is wise to subtract an inch (or two!) from whatever number a guy presents. Continuing the charade IRL can feel like actively thrusting yourself into absurdism. You don't have to lie to anyone for the sake of their penis-shaped ego.
What if, instead of relying on the consumption of media, you relied on your imagination and your memories? You could reminisce about particularly enjoyable sex you've previously had with your wife, fantasize about sex you might have with her in the future, and use embodiment and mindfulness skills (specifically, the ones that focus on being present in the moment and noticing all the details) to soak up the experiences of the weekly-or-so sex you do get to have with your wife (and bank that for future wanking).