Look how worried Ken is when Yohji threatens to leave.  (Omi and Aya are cuddling in the background hoping *their* relationship doesn't get broken up that way...)

 

    Here's a great example of hinting at yaoi in WK for you Yohji X Ken fans out there!
(And Yohji always claimed to be a ladies' man!)
Since this scene might need a little explanation (it's hard to tell who's saying what) here goes...

The Weiß guys are all going on a mission and they split up into a Omi/Aya group and a Yohji/Ken group...
Panel 1: Ken comments how dangerous the situation looks
Panel 2:  An off-camera Omi is concerned and whispers, "Take good caution, you guys!" to the pair before they split off
Panel 3: Ken is just confused, but Yohji liked the way that sounded
Panel 4: Yohji teases Ken about how the two of them should "be careful" together and Ken blushes furiously
Panel 5: Poor Omi doesn't know what he said that was so funny!