Somebody else's kid says they love you?

I don't think this is very controversial, I'm just curious what other parents think!

There is a boy at my daughter's daycare who is super extroverted and talkative. During the summer the kids are usually outside when I pick her up and he would always talk to me. (In the winter they're in the basement and the provider just comes up with my daughter so I don't see the other kids much.) He was 4 or 5 last summer and there was a period where he would always say, "Love you!" as we were leaving. I never quite knew how to respond. The kid is really sweet and funny and I personally don't have a problem saying it back to him if it obviously makes him happy, and I don't think giving love to children is bad! But if you heard some other adult you've only spoken to a couple of times saying they love your kid, would that be weird? We are in an age where everyone is on edge about stranger danger. I'm probably overthinking, I just want to know how others would handle it.