The best way to prevent it from becoming a problem in your relationship is to satisfy your lover first.
You can do this by fingering her or having oral sex.
Wait with intercourse until she is satisfied, so she won’t feel frustrated when you come quickly.
When you ejaculate before intercourse, during kissing or fingering, enjoy it. But let it not be the end of sex. Please your lover with your hands, maybe giving her a massage during half-time. After a while you may get excited again and eager to continue. Guys often last longer a second time around. When you are not in the mood anymore after your first round, just satisfy your partner manually or orally, so she won’t experience your rapid climax as a big deal.