I think it might depend on how "common" this type of relationship is in the society you're building. If it's universal then it would hardly warrant more than a passing reference. However if it's unique it might need have to take up a lot of sub plot if not become the actual plot itself.
Uniqueness would IMO rule out (or demand exploration of) any reference to food, drink, travel, religion, or any of the personal aspects of existence as in
We arranged to meet at the 'Whampa Burger' on the corner of City and Maine. When I got there I ordered my usual; steak, fries, strong coffee and sat back, pretending to read the Daily Routine as I watched the offices across the junction. When she arrived she went for the dead dog and a bucket of slurry. I was glad I'd finished mine by the time she sat down.
The point is that you couldn't really mention anything about daily life without highlighting the differences. If you don't then why have the relationship at all. If you remember the TV detective program about a group of alien refugees that settled on Earth quite a lot of the storyline was taken up in this way.
Then there are other issues. You say the human or none human female (although there's another aspect with a male non human to be written as well) suggesting that there would be the possibility of rivalry between the two females. This also has the danger/opportunity to interfere with the real plot.
A possible twist would be the main character being the alien chosing between the human girl or his fellow Sploggwander.
Of course it's practically expected in Star Trek, so how do think that works?
Personally I don't think it does. As far as I'm aware the universality of procreation success is never explored. For the unions to be so invariably successful then somewhere, way back in time, (Unless the reader is expected to suspend
all knowledge - absolutely - this would be fantasy) the origins must have been the same. This would dictate that basically they all had he same ancestor. Since we know that we are genetically close to chimps and orangutans (by definition closer than something that developed on another planet) they would also be possible mate options which even in SF is a little too unpleasant for my taste: which casts doubt on the potential for such a relationship other than of a purely none physical nature.
I mean really, would someone who actually looked like a Klingon ever be attractive to a human if you didn't know it was a human inside a costume.
Now in fantasy this doesn't apply for there we have 'magic'.