It is forbidden for a man to marry the wife of his son as soon as the son does the marriage contract with her, because Allaah says (interpretation of the meaning):

“Forbidden to you (for marriage) are: … the wives of your sons who (spring) from your own loins”

[al-Nisa’ 4:23].

He may marry the mother of his son's wife, or her sister or her daughter - from a husband other than his son - because Allaah says, after mentioning the women who are forbidden for marriage, (interpretation of the meaning):

“All others are lawful, provided you seek (them in marriage) with Mahr (bridal-money given by the husband to his wife at the time of marriage) from your property, desiring chastity, not committing illegal sexual intercourse”

[al-Nisa’ 4:24].

So there is nothing in sharee’ah to prevent the father marrying the sister of his son's wife.

And Allaah knows best.