Song of Songs 8:1

O that thou wert as my brother, that sucked the breasts of my mother! when I should find thee without, I would kiss thee; yea, I should not be despised.

Cross-reference

Song of Solomon 1:2 likewise expresses a longing for kisses — reinforcing the same theme of intimate affection and desire without shame.

In Song 5:1, the beloved is called 'my sister' — the same sibling metaphor for lovers that the speaker wishes for here.

Proverbs 7:4 calls wisdom 'sister' — similar sibling imagery for intimacy, though here it's about the beloved.