I would say the
worst thing would be having
sexual relations in the
leather chair. The person sitting on the leather would stick, and their skin would get pulled, stretched and
bruised from the
activity. Leather chairs are a bit more expensive, and
staining them would be unfortunate. If you clean the leather with something like ArmorAll, you have a 50/50 chance of slipping off of the chair at the least opportune time. If your
thrashing should become overly
pronounced, you could break the expensive leather chair.
If you still desire to make love on such a chair, I suggest you have a very slow, deep merging with the male sitting on the chair and the woman facing him on his lap (assuming hetero). Take your time to enjoy each other and to touch and caress. Crazed-weasel sex should be reserved for different locations.