As a Christian you should be abstaining from sex until marriage for the purpose of giving that special gift to the one God has set aside for you. To share thae sexual experience with anyone other than your husband would be cheapening it and giving away something that belongs to another.
Until you are married you can't be sure this is your mate. It would be better for all around if you simply abstained from any sexual activity...including the heavy petting etc. The reasoning has several aspects....first...the most obvious is marriage plans may fall through. If you continue to participate in sexual activity then you may be sorely disappointed if the impending marriage doesn't happen. Second....it must be very frustrating for the two of you to arouse each other and then not cllmax. BTW...if you are cllmaxing then you may as well go ahead and have intercourse because you've already violated the "spirit" of abstainence and/or celebacy.
ANY sexual intimacy serves to form a bond between two people who are romantically involved...for women moreso it seems.