Your best friend has always been a cuck. No shame, no judgment--just the truth.
You first found out about it when his college girlfriend broke up with him and came running to you. Turns out he was really into talking about how much bigger you are, asking her to talk about fucking you, etc. She wanted to see if he was telling the truth.
That was the first time you did it.
His wife, though? She's a tough nut to crack. You've been trying for ages, eventually getting really overt at a New Years party, pushing your hard cock against her, grabbing her, kissing her. You could feel the moan she let escape as she felt your thickness rub against her pussy through her dress, but she pushed you away and that was the end.
Until tonight. You're spending the night at their place--while he's away--and you just know that she told him about it, and that he's been using it as fuck fodder since. And you're going to use that to get what you want, and what she needs: your thick cock, lodged firmly in her hungry hole!