There are some adjustments you can make on the passenger floor boards. Stock they are set in the middle so they can move up one notch. if that does not do the trick, there are couple of folks that make passenger pegs that fasten on to the brackets on the passenger floorboards. If all that fails, talk to the guys at Mean City Cycles, They can re-work your passenger section of the seat and leave your part alone.
Take care out there.