This should really be AWBU because it's the same for both of us. We've had location sharing on between us 24/7 for a couple of years now. I can always see where DH is and vice versa. It's hugely helpful and we turned it on for very practical reasons. No more messaging each other where are you, having to explain that we're stuck in traffic, worrying about each other if we're running late etc. It's certainly not to 'check up on each other', there has never been a hint of suspicion of infidelity in the relationship and we both trust each other fully. Days go by without me checking his location, but it's very handy to have there when we need it.
We're both happy with the arrangement, but I said to a friend the other day that I'd just quickly check whether DH was home yet and looked at my phone, and she reacted like what I was doing was really awful. She was gobsmacked and sort of acted like it was a controlling/abusive thing (despite it being both ways). I've mentioned it to several friends since and I've had very mixed reactions. Some couples do the same, some thought it was very odd.
AWBU? Is this a weird invasion of each other's privacy?