He kept her painting

I have a issue That I need your advice and opinion.

I have been with my boyfriend for two years now. We have been great ever since, but there is a painting hanging on his wall and I kept asking who draw this painting for you and he kept telling me that it’s just from a friend nothing more, then I realized that it was from his ex and it was it a birthday gift. after I confronted him he said that he doesn’t have any feelings for her now, and he has no idea how is she because she hasn’t been in his life for about five years (which is true) and it’s just a painting that goes good with his furniture am I crazy to be jealous or is his behavior is not right to me?

If it would be you would you be jealous?