How can you infer that? She clearly had access to his location history, it's extremely unlikely that it happened without his consent. This is rather a vibe of two enthusiastic geeks being genuinely curious about analyzing some cool data about themselves, rather than anyone being "overly attached". We can't tell for sure without more details about their relationship, which isn't our business at all, so talking about "big red flags" feels really wrong and paternalistic (which in fact sounds like a big red flag :P).

> Also, how come 2 people be so ok with Google having all their location history?

That's a valid question though.