Rav Nachman said in the name of Shmuel: Even though a man has several children, it is forbidden for him to remain without a wife, for it is said, "It is not good for the man to be alone" (Genesis 2:18).
A Man May Not Dwell Without a Wife Even Having Children
Yalkut Shimoni on Torah 22:10
אָמַר רַב נַחְמָן אָמַר שְׁמוּאֵל, אַף עַל פִּי שֶׁיֵּשׁ לוֹ לָאָדָם כַּמָּה בָּנִים אָסוּר לַעֲמוֹד בְּלֹא אִשָּׁה, מִשּׁוּם שֶׁנֶּאֱמַר "לֹא טוֹב הֱיוֹת" וְגוֹ'.