Well since you enjoy giving head I think using the double dildo you and hubby should have a competition to see if he gets to cum.
It will have two halves, if he wins one you can give him a bj but he gets a ruined orgasm, if he wins both you give him a toe curling mind blowing bj, If he loses both halves....he gets a ruined orgasm AND must have the plug up his ass (if it wont fit the dildo will be an acceptable substitute)
Either way of course when you finish you spit his cum on the floor and he licks it all up.
Since this is a competition he should be made to dress for it his sluttiest sissy clothes and lots of make up, go especially heavy on the eyeliner.
Event one, sucking dick.
Using the double dildo take as much in as you can in your mouth/throat.
You have ten minutes to get your best score, use where you are holding it to mark how deep it goes then measure the depth at the end of your time, you may stop early if you are confident in your score.
He will repeat the process except he must continue for the whole ten minutes. He may slide it in or out but he may not stop for the whole ten minutes.
Event two, work the pussy
Same deal as sucking except now in your pussy, and now the time limit is extended to 20 minutes. For 20 minutes he will watch you fuck yourself with the dildo, feel free to cum as many times as you want and remind him how he couldn't ever please you like this with his tiny little thing. You should use the whole 20 minutes.
For him...well since he doesn't have a pussy he will just have to use his other hole, he spends 20 minutes fucking his asshole with the dildo trying to take it deeper in his ass than you could in your pussy. You may allow him additional lube but that's your call.
Yes, he will probably lose the first event and win the second but... he will have to push himself to do so.
Added stipulations, he wears the pantie mask again, bind his dick like you have before so whenever it gets hard it hurts, don't tell him ahead of time what the prize is but make lots of vague threats about what will happen if he loses both events.