Disappointed 😢

Hello everyone, My son's grandparents received us for the first time last week but everything seemed to be going well because the lady was so happy that her husband didn't say a word. Before we left, she gave us her number so we could keep in touch. For the record, I am raising the child on my own, which is fine with me, i let the father see the child when he feel like it, but no child support . However, when we were together the father (grandfather) was always cold to me, but every time he was confronted he always found x reason blah-blah-blah to deny that he wasn't cold. I find it strange that on two occasions I called the grandparents because I was going shopping in their area. I thought they might be happy to see their grandson, given the welcome I'd had but no answer 😂 but to clarify the number the lady gave me is the mobile of her husband who is the "grandfather" so obviously he doesn't answer my calls and doesn't return the no's! So my question is: should I keep watering a plant 🌱 to perhaps receive disappointment and create false hopes for my youngster? He's still very young to understand and for this to have a negative impact but deep down I'm at peace with myself knowing that I've tried to create bonds by making the effort and in return I owe them no side. I'm doing all this for my child because I don't care about these people because when I was in a relationship, they didn't give me much importance.