There are methods like dry humping where the male partner might ejaculate in the process. Is this a sin or considered to be similar to the pullout method?

God gave us the gift of sexual pleasure not to exploit it for selfish enjoyment. Sexual pleasure must be merited as the dignified reward and encouragement for uniting with the spouse in love, in the conjugal embrace, within the context of the sacrament of marriage. Sexual pleasure is the right and legitimate reward of the marital act. When we divorce sexual pleasure from the conjugal act, the act is degraded to mere mutual utility or use. To ‘use’ a person is the opposite of loving. The act of using another person of selfish gains is lust. Love calls us to give ourselves totally to the other by willing the greater good of the other. The divine will is that every sexual act initiated between the married couple must be consummated; in other words, must conclude in the procreative act. When we ‘use the other person’ for selfish reasons, we reduce the individuals involved down to mere objects of pleasure.  Such acts degrade the dignity of the individuals and the divine institution of marriage as well. 

The purpose of the sexual act is twofold; union and procreation i.e. for the loving physical, mental, emotional, spiritual and intellectual union of the couple and also to be elevated to the status of co-creator with God by willingly submitting our bodies to the miraculous life-giving act of God. If any one of the above purposes of sex is ignored in the sexual act, the act becomes morally wrong.

In the case of non penetrative sexual acts, there is no union or procreation. And in the case of the pull-out method, there may be union but there is evidently a willful denial of the procreative aspect. Either of the above sexual acts fail to qualify as acts in accordance with the divine will and purpose. Thus these acts must be confessed and sanctifying grace must be restored within the souls of the beloved couple. Stay pure, stay strong. Praying for you.