Being petty

Recently I attended my birth daughter's birthday party. She was more excited to see me than she's ever been, and constantly wanted to be picked up. She LOVED the gift I got her, to the point where she didn't want to open any of her other presents, she just wanted her doll. It made my heart happy to receive so much love, and feel like she's finally understanding who I am and feeling a special bond. But it created kind of an awkward situation- she did NOT want her birth dad. When he arrived, she clung to me and wouldn't engage with him. I tried to coax her in to letting him hold her, but she wouldn't have it. Toward the end she warmed up to him, but mostly she just wanted me. There's a part of me that's being very petty and secretly gloating. That's what he gets for not coming around very often. He was very unkind to me when I was pregnant, the relationship was really terrible and it's because of that that I placed. Now he's not getting as much love because he didn't give her as much love. But it's not right of me to think that way. I should want her to have a good relationship with him. She deserves to feel loved by both her birth parents, and never feel torn between the two of us. I don't want her to feel the anger and hurt that I feel toward him, and I hope that's not why she was so hesitant to go to him. I would never say anything negative about him, and I tried to be nice and to encourage that relationship, but my heart just isn't in it. Thoughts on how to work through this?