I want my husband to do as your wife is asking, because I think it is hot as heck! I have been with guys in college who do this and I nearly came watching with no touching. I get that same feeling every time I think about it.
Next, if my husband could experience the fun I experience when sucking cock and taking cum, that is one more thing we can share. Then we can also share the rewards of that (cum) as well.
Plus, if he sucks a cock with or for me, that means he finally gave in to us having other men involved in our sex life. I am a cum and cock addict, the more the merrier. If we could find a few good men, oh my oh my oh my. I'd never go hungry for cock or cum.
If we had more cock and cum and could share them, my husband would better understand where I am coming from when getting fucked and cummed in by them. Yes he could not only take them orally and anally but the experiences would be as close to similar as when I take them. I believe it will make him even better at it with me (anally).
Last, if we had more cum, our kissing would be even better. Cum kissing to me is the ultimate hot steamiest kissing EVER!