permitted occupier on addendum to current contract or not?

Tenancy Types and Management

Completely new to this scenario. Very reliable, commited single tnt in a 3 bedder for 2 successful years on rolling AST announces pregnancy & wants new AST from March. BF as permitted occupier please, NOT as joint tnt.

Savvy gal I Had thought, up to this point, but hey takes all sorts. Rent WILL be paid. Not sure if the convenient BF is the means to an end, in 5 years time I'll know more!

I don't really relish the 'new' contract process & all that entails. I'm toying with the idea of keeping it 'thimple', until i'm sure its not just a flash in the pan, that my senses tell me it is. . Oh & a small well behaved dog [arn't they all] is in the mix too. He's a handbag dog. as the pic foretells. Smaller than my Siamese, yet will be featured large in the addendum that i'm cogitating on.

My AST forbids pets which is why the tnt is offering a pet bond up- front, or offering extra rent to allay my concerns. The addendum will demand that ANY damage however caused is repaired before I discover it on my 6 monthly inspections, or the tnt foots the repair bill.

Worry is that I up the rent to absorb the pet damage, that thats encouraging the wrong attitude entirely ..encouraging diffident control over the tiny woofie. The house has a suitable garden & is surrounded by doggie lairs. Dogs have to be taken out to these places though or the lawns & patios become doggie loo's.

All suggestions welcome. Never had permitted occupants, nor a doggie, nor a new baby, so steep learning curve . Inclement weather just needs suitable clothing. That in this case will be.... robust paperwork & finger -crossing. Gal is vry house- proud professional, who knows what can happen with a 18/7day fractious baby & a jealous frantic yapper.