Im thinking about renting out the bedroom and just crashing in the living room and I pay the full rent+bills but they just reimburse me their part. Trying to avoid a situation where thats income because it really isnt, its more reimbursing their share, like moving in a partner or something and splitting.

The use either the terms

assign (transfer the right to occupy the rental unit to the assignee so they become the new tenant to the landlord)

and

sublet (original tenant moves out but can return and it doesnt alter tenant/landlord relationship)

I won't be moving out ("subletting"), nor will I be taking my name off the lease ("assigning", I'm simply thinking of renting the bedroom to reimburse their half of the rent and everything else stays the same, I still take care of bills/utilities

All rent would just be going straight to the account with the landlord, i never retain or enjoy it (practically speaking), I would just set their last month's aside for when the last month arrives and apply it to the account then

I have to let them know of my plans and get their go ahead apparently but how do I frame it when neither those terms really captures what I've laid out?

Edit- there's a section on

Guests

Landlord cant prevent having a roommate as long as local bi-laws on occupancy standards are respected