Relationship

We are young couple trying for TTC #1. My age is 27 and my husband's age is 29. Yesterday we went to one birthday party which is for my husband's colleague son. They are quite close to us. Everything goes well at the party. While leaving they gave return gift to all those who have kids except us. Is this common in foreign countries? (Like ignoring couple or individual) I can accept that they may planned return gifts only for kids. If so why should they invite us ? They can celebrate the function with kids or those who have kids. It bothers me a lot. Why people are not thinking about others ? I just wanted to express this through the post. Btw if it's wrong to think like this I'm sorry I can't made up my mind.