Possible Clues:

• #1 pal, lately
• With whom you might have a Snapchat streak, informally
• Very close pal, informally
• One who likes every one of your Insta posts, say
• Person who likes all your FB posts, perhaps
• Person you're rly close with
• Partner '4 lyfe'
• Many a maid of honor, informally
• Close bud, for short
• Inseparable pal, for short