This is Xena kissing Gabrielle on the cheek at the latter’s wedding to Perdicus (a man, to avoid confusion). Not too strange a thing in itself.
Gabrielle has been put into magical sleep and is awakened by a kiss. What’s that term - fanservice?
As riker1384 explains, this is inside Gabrielle’s head (or something, it’s not clear). This is quite explicit, though - it’s pretty clearly an actual loving on-the-lips kiss, even if they don’t show the last second of it.
Xena needs water from a particular well to regenerate, so to speak, and poor Gabrielle can’t find anything to carry it in except her mouth, but a good platonic friend’s gotta do what a good platonic friend’s gotta do, am I right? And when she slips her some tongue, that’s absolutely necessary. Yep.
They never made it explicit, but there are a few scenes that, to my mind, cannot really be taken any other way. The last two pictures are examples. In the last one, Gabrielle and Xena munch on each other in what is supposed to be an attempt to revive Xena with magical water.
[li]In a first-season episode (before the writers admit they did the subtext intentionally) Gabrielle and Xena have an argument, and Gabrielle spends the night with a guy. In the morning, they meet outside his room and Gabrielle is all “I didn’t have sex with him” and Xena is all “Doesn’t matter to me, none of my business”. To me, that was a “we haven’t quite defined our relationship” tiff.[/li][li]When Gabrielle is marrying Perdicus (also before the intentional subtext, if the writers are to be believed), Xena does not look happy. She just doesn’t. She puts on a brave face, but she doesn’t like it.[/li][li]In the episode “Heart of Darkness”, they do a dance scene together that really should be seen.[/li][li]Also in “Heart of Darkness”, Xena is going seductive on an archangel and is hit in the back of the head by an object thrown by Gabrielle who’s sporting a very “and what the hell do you think you are doing?” look on her face.[/li][li]At one point, Xena has to hide under water and a (female) character called Lao Ma goes under to give her air. With her tongue.[/ul][/li]There’s also a lot of bathing scenes, Xena introduces Gabrielle as her soulmate, they often say they love each other, and so on and so on.
We also have the Amazons, an apparently all-female culture. Don’t tell me they don’t get freaky. On the other hand, one young Amazon doesn’t know what kissing is in one episode. On the third hand, one very hot Amazon describes guys as “totally dispensible”, but (on the fourth hand) falls for a guy a little later.
Basically, they just had a lot of fun with the concept. I would have loved it to have been made unambiguous in the final episode, but it didn’t happen. There was the “Sappho episode” floating around that was never filmed because they couldn’t figure out how to make it without turning subtext into maintext. Bah. If I’d been in charge I would have done the Sappho episode as the very last episode and moved the final episode one step back instead. End the series on a note of love instead of grief.