Is it safe to assume that a customer had a girlfriend/wife/sister?
Why would you assume a customer had a girlfriend/wife/sister?
They just look like the type to have a significant other
Assuming things about other people is unnecessary. Not every person you run across will have a partner and you can offend someone by assuming things.
Stop assuming that I'm offending people. I'm not.
Maybe it's not offensive to you but people might find so. It's illogical to guess if someone has partner or not just by looking at them.