How to eliminate sexual urge for in a relationship Christians?

How should an obedient Christian eliminate his libido while he or she is with his/her boyfriend or girlfriend?

remember that fornication is one of the works of the flesh that a Christian should never do (Galatians 5:19-21) even you'll use contraceptives to prevent venereal diseases and unplanned pregnancy.

Fornication is cheating on your husband or wife. It has nothing to do with sex before marriage
Sex before marriage doesnt evwn exist in the bibl the, way it is traditionally portrayed

I don't think there is such a thing, brother. God made men and women, and he made them to desire one another. Those desires are something to guard against as an unmarried person, especially when you're getting close with a special person in your life. Even if there is a way to totally avoid sexual desires during your dating phase (ELIMINATING it is impossible), there are no pat answers that someone can give to work in every case.

Everyone is going to have problems with different things, and it is important that you communicate those problems with your beloved. Maybe you need to watch how much time you spend alone, limit the amount and type of touching and loving expressions, dress slightly differently, etc. Rules and boundaries are a good thing, as long as they don't become Pharisaical. Remember that the key point to all this is to glorify God by doing what He wants...you don't somehow get brownie points for saving your first kiss until marriage. It may be a tool you use to keep God as your focus, but to think of it as more than that is treading on dangerous ground.

You don’t eliminate the urge, you just control it. Have common sense like don’t go into her bedroom or she go into yours. You eliminate the opportunities for sex, you don’t eliminate the urge.

You eliminate the problem by setting boundaries in your relationship. If a simply touch on the knee or even holding hands get you hot and bothered , then do not even do it. Let your partner know that you will not touch, hold hands, or even kiss to prevent fornication. If you do all of the above and still find yourself desiring to do or you have sex anyway, then you should find the root cause of the problem (could be lust) and or fast/pray (intensely).

Take a cold shower.

Self control is a gift from Holy spirit, if not, the only other remedy for sexual urges is marrying.
Sexual urge is not an issue IMO, it is natural. Sexual urges can lead to sexual sin.
A sexual sin is a sin against ones own body/flesh- do you know why? Because a man shall leave his parents and be joined to his wife, the two shall become one flesh. Sexual sin corrupts the love that binds partners, the love that makes them one flesh or one body.