The reality is...
Your house, clothes and car will smell. Lots of dog people claim their house doesn't smell but it does, you just become immune to it. You don't realise until you've been away on holiday for a few days and come back. I have dogs known for having little/no 'doggy' odour and even my house pongs a bit. A waterproof, greasy, historically working breed like a lab or a spaniel will stink even more, as will a jowly drooly dog.
They bring an insane amount of dirt into the house - hair, mud, dust, dander. If you are even the slightest bit houseproud, don't do it. The house will never be clean. Their paraphernalia takes over - stair gates, beds, crates, bowls, mats. There will be piss, crap and puke in varying amounts - even a healthy adult dog will very occasionally produce exorcist-style vomit or diarrhoea on three walls, the carpet and the sofa during the night.
They can be a drag on holidays. You have to find a dog friendly campsite or hotel, possibly paying extra for the privilege, and dog friendly pubs or restaurants. Dog cannot be left alone in car, tent or hotel room. Lots of attractions the kids will want to visit won't allow dogs. I adore holidaying with my dogs but everything we do is centred around them - we run on the beach, we climb mountains, we visit other venues for our dog sport.
They are a tie. You always have to get back for the dog - no more day trips, lie-ins, nights out without paying kennel or dog walking fees. Walks must be done every morning and every night, regardless of weather, regardless of human illness, kids included. Everybody has to be on board with walking and training.
They are wonderful, rewarding, I wouldn't be without them but it's a lifestyle change at least somewhat akin to having your first child in that you are suddenly responsible for this living thing and nothing quite prepares you for it. I remember the first few weeks being incredibly stressful - I had headaches, nausea, constant anxiety, many times picked up the phone ready to call and return the dog - and I had always had dogs in the family, the only difference being that this was my first that I'd had full responsibility for.
I am not trying to put you off, just making sure that you are truly prepared for the lifestyle change you'll undergo if you do want to get a dog.