Was this a work colleague? If so, isn't your relationship transactional and just part of a larger transactional relationship. That between each of you and your employer.
Human relationships just can't be boiled down to a single term in that way. My relationship with the cashier at the grocery store is obviously transactional, yet we can interact in a variety of ways, and how we do so will affect how we feel, how satisfied we are with {the job|the store}, etc. There's always room for two people in an interaction to be more or less trusting, compatible, enjoyable, etc.
Honestly when you boil it down, almost all relationships we have are transactional to some degree (money, emotionally, physically...). Unconditional love is very hard.
