All acts that aim at satisfying and pleasing the spouses are allowable so long as two things are avoided, that is anal sex and having sex with a wife while she is still in her menstruation. Thus, it is permissible for a husband to kiss his wife’s vagina and a wife to kiss her husband’s penis.
In this regard, Dr. Ali Jum`ah, mufti of Egypt, says that licking, sucking and kissing spouse’s sexual organs are all allowed, as long as it gives a person sexual gratification that will keep him away from haram (unlawful) or starring at opposite sex (marriageable). But every Muslim must keep in mind that sexual intercourse is just a lust and passion that must be satisfied in a lawful way; it’s not to be perceived as necessary as foods and drinks.
Having stated the above, we do advise Muslim married spouses to always bear in mind the objectives of the marital life in Islam, so that they will be pleased in this world and the world to come.