hmm. Tried watching a sexy film together? Not porn just a sexy film. Gives you an excuse for wandering hands on the sofa, and he's more likely to let you since men are more visually stimulated than women.
Has he always had a low sex drive, or is it a recent development? If it's a recent thing maybe it's that he can't seperate you from "Mummy mode" in his mind to be the dirty sex godess he was used to before they came along (I'm assuming you have kids, here!) or that he's a bit depressed with work or home life.
Another thought, if you haven't had sex for a long while, is maybe he's having problems in his downstairs area? Maybe he's worried he might not get an erection and doesn't want you to know, or for him to have to discuss it.
I think if his loss of interest in sex has come on recently you have a right to question him tactfully about it, after all there are myriad reasons why someone can lose their libido, anything from a reaction say to antidepressants, depression itself, emotional changes etc
In the meantime if he's still giving you cuddles and telling you he loves you, take matters into your own hands until he resolves his issues, and if you think he might feel upset that you're taking care of your own pleasure then dont let him catch you at it. Or if you think it might turn him on, do let him catch you at it!
Just not with an enormous plastic phallus in your hand. Might not go down too well.