@westkate, technically, all friendships make Love Bank deposits.
But when an opposite-sex friend meets the most important emotional needs of:
• affection (expressions of care and concern),
• intimate conversation (conversation about personal problems being faced, and topics of personal interest),
• recreational companionship (spending time together enjoying common recreational activities),
• honesty and openness (revealing personal feelings, past history, present activities, and plans for the future),
• physical attractiveness, or
• admiration (expressions of respect, value, and appreciation),
...
romantic love is almost sure to follow.Link:
The Risk of Opposite-sex Friendships in Marriage