See, the second season is set in the 70s, when Steve Trevor Jr is on a plane that wanders into Paradise Island airspace during a hijacking attempt. Diana goes on, sees that everyone is unconscious and there's a guy on there who looks exactly like Steve Trevor. And she knows several decades have passed and this is impossible. It turns out to be his son, and her Steve has recently died of old age. As she can assess there's an obvious danger to the guy, she asks to go back.
We have a different Hippolyta, a redhead this time, and she's the best one yet. She wants to deny it, but they put it to a council vote and Diana just has to face one challenger in Bullets & Bracelets before she's off to Man's World again.
Now, from the start it looks like they want to continue the same character dynamic, but it doesn't work. They changed his character. She was in love with his father, not him. He was raised on stories about her, and of course he geeks out when he sees her. At the end of the show they even do the thing where Diana misspeaks and says "Well, I'm sure she came back for you--I mean us" when speculating about Wonder Woman's motives. (This was common in the first season. We'd see him get this modest/embarrassed look after she made those slips, because it was obvious to everyone from FDR to General Blankenship's dry cleaner that the most beautiful woman in the country had a crush on him.)
Jessica Walter (I don't know her character's name but fuck it, it's Jessica Walter) picks up on Diana Prince's looking at him and they even try using an imposter Steve against her. (Who comes onto Diana Prince and chases her across the apartment until she locks herself in the bedroom, changes to Wonder Woman, and comes around the building to
After the first episode, though, they seem to put this aside and it's just a professional relationship. I don't know if that was the actors being unable to adjust the character change, or the writers just discarding it. Either way, it didn't work and I think it's because it wasn't really her Steve. She wasn't following him around because she loved him so much as she was protective of the kid of a guy she loved. I'm only about halfway through the season, but they seem to have settled into close platonic friends. He's a pretty important part of the series as her boss, closest friend and most influential ally, (and he still admires the hell out of Wonder Woman) but I do not see these two dating even casually.
When he gets promoted to being her boss he gets moved off the frontlines, so they cool a bit further. She has solo adventures and when they want to pair her up they come up with a brand new male character for each episode. It's really close to the Rooster Roulette we've seen post-Crisis. I think this was more because they realized Lynda Carter could carry the show all by herself. (Either that or Waggoner was sick of being tied up every episode.)
Funny thing, though, I think this demonstrates a way to keep older Steve and bring back a love interest Steve. Steve Trevor will be a different character according to the period of time he was raised in, he'll default to that generation's healthiest expression masculinity combined with a progressive view (and genuine like and respect for) of women. That's different for a guy in the Army in the 40s and a guy in a spy service in the 70s even if they are played by the same actor. That's going to be different for a guy born in the 40s and a guy born in the 80s. It's not a bad shot on either version of the character, it's just natural.
So, why not go the way of the TV show and introduce a younger character of the same name? They could retcon the first couple Perez stories a little (to add that Steve was married before) or a lot (to substitute the younger Steve for the one who crashed on the island) if they like. They can write out the backstory of the mother and what happened to her. Because Diana never had romantic tension with older Steve, they'd be free to explore the younger version as a love interest. And they can go into the future with the family, because old Steve would undoubtedly have dad angst and Etta would have to deal with a stepson who is very close to her own age.
Of course, then there's always the problem of where has this guy been all these years. For that, I have a convenient plotmaking chart. Just fill in the blanks from the appropriate column:
Steve Trevor Sr's (Column A) of the same name has been (Column B) for many years due to the machinations of (Column C), who took him (Column D). Diana must fix this.
And I've also made one for any future storylines they might need. With decompression, this should last them another 600 issues.