Dude. It really depends on the sexual needs of each partner. I
don't know how prudish Singaporeans are nowadays but sex is an
intergral part of a relationship. Regular (and satisfying) sex is
important and is indeed one of the many causes of the breakdown of
a rs. If you are a god damn horny beast and your gf is a dead fish
who doesn't enjoy sex, I suggest you communicate this need to your
partner and if it can't be resolved / compromised, look for another
girl.
If you can't marry the right one, don't marry at all. PEACE