ðɛɹ ɹᵻlˈeɪʃənʃˌɪp bɪɡˈæn vˈɪzᵻbli dɪtˈiəɹɪɹˌeɪɾɪŋ ɪn wˈʌn θˈaʊzənd fˈoːɹhˈʌndɹɪd twˈɛnti θɹˈiː, ˈæftɚɹ ɐlfˈɑːnsoʊz ɹᵻtˈɜːn fɹʌm nˈeɪpəlz ænd əpˌɑːn lˈɜːnɪŋ ðæt hɜː hˈʌsbəndz ɪtˈæliən lˈʌvɚ, dʒˌɜːɹɐldˈoʊnə kɑːɹlˈiːnoʊ, hæd ɡˈɪvən hˌɪm ɐ sˈʌn, fˈɜːdɪnˌænd.
Their relationship began visibly deteriorating in 1423, after Alfonso's return from Naples and upon learning that her husband's Italian lover, Giraldona Carlino, had given him a son, Ferdinand.