There are a plethora of moments between the two. For one, there is Belle's tendency of referring to Tari as "honey or "babe" in nearly all of their interactions with each other.
Episode 1:
Belle playfully taunts Tari when she asked her for tips on how to do the gaming glitch featured in Ultra Jump Mania.
Episode 2:
Belle shows concern for Tari when Lucks' attempts at harnessing Tari's game-warping abilities puts her in immense pain.
Episode 3:
Belle grabs ahold of Tari's arm when she cryptically tells her that she wouldn't believe what people would do to be the best, leaning in close with a low voice in a very suggestive tone.
Episode 4:
Belle tries to make Tari feel better about her being kidnapped by saying that if she were to see how Silica City was truly like, she'd crawl back to TASCorp without a second thought.
Episode 27:
Belle calls Tari "babe" several times in a row here.
Other
In Season 2, Tari (reluctantly) dates Satsuki-chan in Pocket Gakusei in order to find Lamar's username, but turns down her love confession in the end.
This ends up coming right back around in the series finale where Satsuki-chan saves Tari from being killed by the brainwashed Lucinia.
Similar to the above example, Meta Runner: Source shows that Lucinia also dated virtual girls in Pocket Gakusei.
