Hi.. my husband has a son from a previous thing before we met. So he is 11 now and all through the years he hasn't seen his son since 2011?

And we have tried to ask her to see him and she said the child doesn't want to, and that her child calls her boyfriend dad, and he doesn't want to see my husband.. We met a few weeks ago by chance and he spoke to me and my husband and our 2 kids, the little boy loved our kids. But when my husband text the mother a few days later to see how his son is she said he's fine and never mentioned my husband (his father) or our kids? Anyone know what we can do? We're both actually heart broken and don't know what to do now 😭😭😭