Hey ScottBunny -
My OH is also a biggish girl, & she also gets self conscious about her 'wobbly bits' (which I've renamed her 'jiggles' - I reckon it sounds less unpleasant, and more fun - which they are!). I've reassured her many a time that I love her to bits, jiggles or no jiggles, as I'm sure you're husband has too (if not, give him a clip round the ear from me! ;-) She does still worry about things wobbling it when we're going at it though... the best advice I can give is "don't worry" - I know it's hard but, from my perspective, and as someone said above, when we're getting it on I'm looking into her eyes, I'm looking at her tits, I'm looking at my thing going into her thing - what I'm not looking at, or at least not thinking about, are her jiggles. Anyway, the more bits I can get wobbling, the better things are going!!
Position wise, our faves are "missionary" - of course (as mentioned, just look straight into his eyes - hot as hell, he won't be looking elsewhere); "doggie" - this is perhaps the one where Ms SWW worries most about her jiggles, but it's totally worthwhile - function wise I think it may be the best for big girl/smaller guy - I think she gets the best sensations from this, and great for me for the fantastic view of penetration; "scissors" - this is the trickiest to describe, but it may fit with your want to hide your jiggles... it's usually our 'Saturday morning wake-up' position... it starts with me behind her on our sides 'spooning', then my top leg goes between hers, her top leg kinda goes over my hip, our top halves seperate a bit, and in it goes. Tricky to describe, easy to do. It's not really a position for heavy thrusting but it's very good - we usually start with that then roll in to missionary to finish. You could also try feet on the floor, bent over the bed, with him standing behind - that way your front is flat on the bed so you have no room to wobble, but you get all the pleasure of doggie.
There are plenty of other options as well of course - if your hubby is anything like me (i.e. an average guy) - your desire to try new positions will be exciting enough that bits wobbling will be the last thing on his mind.
One other idea - if the hubby is open to the idea, have you considered trying a bit of light bondage? - preferably with you in the dominant role. Even just a simple blindfold could work wonders - that way you can have your way with him without worrying about him seeing anything at all. I find that Ms SWW, who usually leans towards the sub side in the bedroom, can become a totally different, and much more confident, girl, on the occasions when she has me tied down and blindfolded & gagged.
Most important thing - remember it's just sex - it's supposed to be fun! Enjoy yourself and let go of your worries!
....if all else fails, strap one on and stick it up him - then his eyes will be watering & he certainly won't be worrying about wobbles! ...ok, maybe that one is a bit extreme (works for us though ;-)