This is an appeal by the wife from a divorce decree which awarded custody of two minor children to their paternal grandmother.

There is nothing unlawful per se in placing a minor child in the custody of one who is not a party to the unfortunate marriage. Gee Watson v. Watson, 213 Or 182, 323 P2d 335, 221 Or 138, 350 P2d 694. The Watson case indicates that such a placement ordinarily should not be considered permanent.

The appellant is challenging the trial court’s finding that she is unfit to have custody, however, and only incidentally its finding that the best interests of the children would be served by placing them in the home of their grandmother. We assume that when one of the parents becomes able to provide a suitable environment for the children, the court wall give the matter appropriate consideration.

The evidence, which need not be set forth in detail, fully discloses a foundation for the trial court’s belief that the mother was incapable of providing a proper home for the children. Her incapacity may not have been caused exclusively by her moral inadequacies, but it is nonetheless real. The affair she was having with the man who wanted to supplant the father was only one symptom of her immaturity. The trial judge no doubt considered the others. In such matters the decision of the trial judge is entitled to great weight. Shrout v. Shrout, 224 Or 521, 356 P2d 935.

Affirmed; neither party to recover costs.