My wife's bull/boyfriend has a MUCH bigger cock than me. He has definitely resized her pussy. I don't think it will ever grip my dick the way it used to.
Her pussy now has several stages after she's been with him.
1) Fucking her immediately after. Her pussy is puffy and swollen. It's like fucking warm, wet cloud that caresses my dick all over.
2) Fucking her a day or two after. Her pussy is a cavern, gaping and stretched. I can practically feel the air around my dick.
3) Fucking her a week or so after (If she miraculously goes that long between seeing him). Her pussy is loose, but there's still some friction. At the right angles I can just hit the spots she loves.
That's about as good as it gets. She hasn't gone more than 3 weeks without his cock inside since she started seeing him last summer.