I was reading one of the answers to this question and it implied that Talia Winters and Susan Ivanova were involved in a same-sex relationship on Babylon 5. This came as news to me, as I own the entire series and never once believed their relationship to be more than just a friendship, no matter how much the teenage me might have wished otherwise. Is there any evidence that the two were actually involved romantically?
Yes, they were romantically involved, though it was for only a brief time before Lyta revealed Talia as the spy with the implanted personality and the original personality of Talia was destroyed. The episode Divided Loyalties, where this happens is also indicated as the first, and perhaps only, time when they were intimate.
The show notes and other discussions from JMS make this pretty clear. There were indicators in the episode that some people thought perhaps a kiss was edited out (it wasn't) and where Talia wakes up in bed and appears to reach out for someone (Susan) who was no longer there.
It isn't entirely clear, but this quote from the creator implies that while they were heading there, they didn't actually get physically intimate:
Susan and Talia had been dancing around one another for months; that night, though, would've been the first time they got physically intimate.
It would have been the first time they got physically intimate. He's not saying that it was the first time.
As for a not-yet-intimate romantic relationship, there was even less officially said, but the fan-notes at the top have a good breakdown that also seems to imply "no" (by way of the first three bullets in particular), but that it was probably where they were headed.
- At the start of the episode, it seems clear that they are just friends. Talia would not hesitate to impose on Ivanova's sleeping quarters if there were anything stronger.
- During the episode, as Ivanova becomes more and more worried about revealing her (limited) telepathic ability, she relies on Talia during the expression of her feelings and doubts. There is an apparent emotional tension between them that might be interpreted as a "should I make the first move," or as Talia's giving support but hesitating to probe further, and Ivanova's "should I trust her, even though she's a telepath?"
- When Talia wakes up in Ivanova's bed, finding her missing, it is tempting to jump to the "obvious" conclusion. However we know that Ivanova's quarters only has one cot (indicated in "The Long Dark" by Dr. Franklin.) Of course, Ivanova probably has a sofa/couch that might have been used.
- When Ivanova has her final conversation with the dominated Talia, she indicates that it gave Talia the words that would get her close to all Ivanova knew. Just how much Talia knows about Ivanova is unclear, and we have no indication of just how close in addition to the emotional bond.
- Had Ivanova and Talia had a physical relationship then Ivanova might have revealed her latent telepathy ("Do you know what its like when telepaths make love?" in "Mind War.") Since the alternate Talia didn't goad Ivanova about this, then either Ivanova maintained a block, or they didn't have a physical relationship.
(Note that these are not bulleted on that page, it's just easier to read them like that here)
Yes, Ivanova and Talia Winters were always slated to be a sexually active lesbian couple;
JMS told Sci-Fi Universe (March 1996)
"We had it growing since the very first episode of the first season. The relationship was about all of that mutual antagonism that really means they're attracted."
Andrea Thompson (who played Winters) stated in "Creating Babylon 5" that:
"There was a sexual relationship between Talia and Commander Ivanova. It was edited so that it was not blatant. But that was exactly what happened. It had been talked about from the very beginning" (The Creating of Babylon 5).
An SFX Interview in July 1997 showed that they wanted to explore the relationship further
"I think that if Andrea Thompson had not left, we would have definitely explored the relationship further. That was the intention, but because she wanted to get out, we had to wrap it up quickly"
Claudia Christian also made it abundantly clear that her relationship with Talia was based on a mutual sexual attraction:
"I'll be quite honest, I was like the lesbian poster child; I got a lot of people writing to me from the armed forces and so forth, who loved the fact that they thought I was going to be gay. I'm not gay in real life, and I don't think I'm gay on the show, but I definitely think she had some kind of thing with Talia. I think a lot of gay women were hoping for that, and I didn't want to disappoint them; I thought it would be fun... Then Andrea left the show, so that's why it never came to fruition. The only reason it didn't go further is because we had to get rid of the character because Andrea wanted to leave. It could have been a long relationship." The Official Babylon 5 Magazine : June 1996
JMS (on the excellent Midwinter website) made it clear that they were involved with each other both sexually and on an emotional level;
Susan and Talia had been dancing around one another for months; that night [e.g. Divided Loyalties}, though, would've been the first time they got physically intimate.
Then there was that later episode when the senior staff had to reveal to Delenn (as part of some Minbar ritual or other) something that they had never told anyone else and Ivanova's secret was that she thought she "loved Tahlia."
Plus Ivanova's whole thing about keeping her telepathic identity hidden her whole life, until she finally "comes out" to Sheridan. Pretty clearly a coded reference to being an in-the-closet dyke (and the self-loathing that that sometimes entails, particularly for people in certain cultures, with certain upbringings etc.).
After the coup in Season 3 Susan tells Delenn during the impromptu Rebirth ceremony that she "thinks she loved Talia". The further evidence has already been presented (almost every joint scene in "Divided loyalties" in Season 3). It seems like JMS had to accelerate this portion of the arc due to Andrea Thompson's early departure from the show. It certainly is an important portion of what we know about the Ivonava arc and the truncated Talia arc seems to have robbed us of one of the subtly potent portions of JMS's progressive sci fi creation and 1990s social commentary.