Scripture affirms that St. Peter was married at one point, since Jesus’ healing of his mother-in-law is noted (Matt. 8:14-15). In this article, Catholic Answers founder Karl Keating makes the argument that Peter was a widower at the time.
More to the point, contrary to what some Christians think, Jesus extolled celibacy in service of the kingdom of God (Matt. 19:10-12), as did St. Paul. And like Jesus, Paul lived what he preached, opting for a God-ordained mystical marriage with the Church as an apostle/bishop (1 Cor. 7:7-8; 25-39; see Eph. 5:21-33).
For more on celibacy and the ministerial priesthood, please see this Catholic Answers tract.