Person radical on the left marks 侣 as a human role - a companion or partner. The two-stroke variant of 人 anchors most relationship words: 你，他，伴，仁. A companion is fundamentally another person beside you.
Right side supplies the sound: lǚ → lǚ (exact match). 吕 pictures two mouths stacked, an ancient symbol for a pair of matching musical tones - and that 'paired, matching' image lingers as a memory hook for the companion-pair meaning of 侣.
