**Based on what you’ve described, I wouldn’t recommend tracking him down solely because a relative is pressuring you.** Your son’s questions deserve attention, and you can give him that attention while deciding separately whether contact would benefit him.

His father’s years of silence tell you he hasn’t participated in parenting. They don’t tell you exactly why, or whether he would be dependable now. I’d base any decision on his ability to offer safe, consistent involvement.

Your explanation about different families gives your son room to ask questions. I’d also make space for his particular feelings: he can love his family and still feel sad or curious about his biological father. You might say:

> “You have a biological dad, but he hasn’t been here as you’ve grown up. I don’t know why he hasn’t stayed in touch. You didn’t cause that. You can always ask me questions or tell me how you feel.”

Keep answers short and follow his questions. The American Academy of Pediatrics recommends simple, honest explanations, reassurance that children aren’t responsible for parents’ separation, and patient listening. Its guidance concerns separation and divorce, but those communication principles are useful here too. [AAP guidance](https://www.healthychildren.org/English/family-life/family-dynamics/types-of-families/pages/Adjusting-to-Divorce.aspx)

I’d gently adjust the message about your fiancé. “He can be your dad when you say so” puts a significant decision on a five-year-old. You could say: “He loves you and wants to help care for you. You can call him what feels comfortable.” Let their relationship develop, with the adults taking responsibility for commitment and care.

If you eventually choose to reach out, make the initial contact privately, before creating expectations for your son. Assess whether his father can sustain contact, then consider a gradual introduction. Any history of abuse or safety concerns would need to shape that decision.

For the relative, a clear boundary is reasonable: “I’m listening to his questions and thinking carefully about what would help him. Please stop pressing me to contact his father, and don’t make promises to him about it.”

**You can leave contact alone for now and revisit it as your son’s questions and wishes develop.** You don’t have to settle his entire future relationship with his father today.