Lift item with Bob
You lean down, grip the item, and look at Bob expectantly.
Lift item with Steve
Bob leans down, grips the item, and lifts.
It would set you both automatically following each other, both hands full, so you'd be able to walk together carrying an item with your combined strength, but unable to hold any other items while lifting.
Strength and agility would obviously be a factor here, the combined strength and agility of the two of you maybe(or maybe 85% of the combined stats, no team is perfect).
This would allow players to lift big heavy corpses and items with a friend, but with the both of them being occupied they would be highly susceptible to being jumped/dipped/etc.
The obvious argument against such a change is: "Just a hire a super strong person, this isn't necessary" and it's a perfectly valid point, just thought it would be a cool feature to encourage players working together in funny little ways.