Go for something really textured, that could in no way be seen as natural--- also, if he has a problem with being quick to cum tell him it will help to prolong his orgasm (does for my husband as it partially deadens sensations)..

My husband and I both really liked the 7 stimulator rings set. I showed my husband a picture of them on the site, and I just asked "do you think these look like fun?" Of course I got asked if I was saying his cock wasn't good enough for me, and even though he said it under jest, there was of course some concern. I just pointed out to him how thin they are, and that they really wouldn't provide any added size, just some fun textures. I stress how much my husband liked those sleeves in my review of them, because I was amazed that he actually enjoyed them so much. I think it's key to not get sleeves that are too thick or alien looking. My husband really enjoyed being able to see his penis clearly through the sleeves, and I'd say that we enjoyed them equally. I'd suggest perhaps reading my review of the sleeves then bring it up like this "I read a review of some penis sleeves today, the woman's husband reportedly enjoyed them as much as she did. Maybe we should try something like that, what do you think?" You could then show him the review and shop for a sleeve together, letting him make the final decision. It might help to say something about wanting something that allows you to still be able to see and feel his cock, just so there is no doubt in his mind just how awesome you think he is.

Is he already very insecure about the size of his penis? If he is, then yeah, this going to be tough, and starting small--with something that adds more texture than girth--may be the best way to persuade him in the right direction. Then you can work your way up to girthier toys.

I'm a big mouth, so I'd probably just say that I wanted more girth, but I tend to sleep with people who are just as mean as I am, so what I would do is usually not a good idea.

LOL at "people just as mean as I am."

I don't think he's very insecure about it at all - I just want to cover my bases.

Then it shouldn't be too hard. He knows you like his cock just the way it is. =) Start out with a sleeve that's more textured than girth-adding, then move on to adding girth. I think that keeps most guys feeling secure.