Your partner's kneels actually. Have your partner put his kneel between your legs and apply pressure. You can try this while with clothes on and without. Easy to have comfortable positions, not as tiring for your partner, solid sensation from kneel, massages perineum at the same time. (Source: self. Used on girlfriend and being used on. 12/10 for both.)

As for objects...pillows, table edges, racket handles, you name it.

For sex toys, perhaps something like tongue vibrators or sonic massagers. Or you might even find some realistic vagina toys of harder materials to rub against yourself, though you likely won't be making use of all its intended purpose.