Kylie & Tyga -- Back In The Bedroom (PHOTOS)

Kylie and Tyga just can't quit each other.

Tyga posted a pic early Friday of Kylie sitting on a bed with the caption, "They always come back..."

Now ... time to connect the dots. A short time earlier, Kylie posted a pic of her wearing the same dress as the one in the pic Tyga posted. 1 + 1 = banging, correct?

Tyga apparently had a change of heart and deleted the photo, but it's pretty clear ... they want people to know ... there are benefits in friendship.