First off the average is 5.1-5.5 so he isn't really that small. secondly you have to know his feelings, you may want to offer him a new experience if you are asking for one. It's not fair if you get to try another man without him trying another woman. and if he isnt okay with it get a toy that he can use on you, so you get the size and he doesn't get jealous.
that's the better way to go anyway
and I'm a big dicked guy living in the northern part of SC
so for me to say it lol