This hasn't happened to me in over 20 years! When it comes time to insert the larger penis, it goes in only so far and because of the 1/2 inch bigger girth, it becomes rather painful and we have to withdraw. I have given birth twice over the years and both have been by C sections because I was told they were not able to make it past my pelvic bone. 

  My question is will my vagina eventually stretch to receive the larger girthed penis without causing any physical damage? (After all it's only a 1/2 inch wider.)  And does this all tie in with the fact that I could not have natural births?  I look forward to hearing from you and thank you so much for all you do!

I am using your question because I think it’s a great example of how it’s never too late to expand your sexual horizons and I applaud you for experimenting like this. I also applaud your husband for agreeing to use a dildo on you just for your pleasure. Many men might feel threatened, but he clearly understands that in the end, his sex life is being improved because you are getting this added pleasure. But as to your question, if the 8” inch plastic penis is giving you such pleasure, and the bigger one is causing you pain, instead of worrying about it, you should just accept the fact that there is a limit to which the size of the dildo causes a positive effect. You were going to reach a limit at some point anyway, so you’ve discovered what it is so leave it at that.