In Islam, physical contact between members of the opposite sex is prohibited. Most people think a handshake is a normal thing to do, but some Muslims would not even want to shake hands with the opposite sex.
According to the hadith of Prophet Muhammad (PBUH), he said that it is better for a Muslim to have a nail driven into their head than to touch someone who is not of close relations to them (non-mahram).
A Muslim is allowed to look for a spouse only if there is an intention of marriage otherwise it is not appropriate since there will be just two people doing nothing but wasting each other’s time. Even the period of “dating” is when the man asks the woman's parent if he can see her and then they get to know each other but with no physical contact.
And if they like each other, the man then tells the woman’s parents that he would like to get married and that is when they get engaged. So, yes, it is not allowed for Muslim people to kiss or touch a person who is not of close relations to them and they are not married to them.
Jabir Ibn Abdullah reported that the Prophet (peace be upon him) said: “When a man is going to ask for the hand of a woman with a purpose of marriage if he is able to look at what will induce him to marry her, he should do so.” (Abu Dawood, no. 2082)
A Muslim may only come in physical contact with a mahram. For men, mahrams include all Muslim men, parents, grandparents, siblings of parents, spouses, siblings, parents of spouses, and off-springs. For women, mahrams include all Muslim women, parents, grandparents, siblings of parents, spouses, siblings, parents of spouses, and off-springs.
The idea is simple yet it is something many who do not belong to similar cultures find it hard to understand. In Islam, intimacy is considered important, almost holy for the lack of a better word, and it cannot be achieved on a whim.
Even marriage does not have the connotations of bondage, as it does for other people. Instead, it is the finalization of their intentions to spend time creating a life for each other, a promise they make to each other, to devote their lives to the joy of another.
The devotion, as well as mutual respect, is the price of intimacy.
It is safe to say that Islam is not a religion that prohibits kissing or considers it bad. It is simply asking Muslim people the question, “Are they ready for the burden that comes with it?”
If they are parents, brother, sister, or anyone considered ‘mahram' i.e. a close blood relative who is not allowed to marry then non-lustful affectionate kissing with the exception of that on the lips or private parts is fine. It is actually Arabic custom to kiss either side of the cheek when greeting loved and dear ones.
However, if they are not mahram, then any physical contact including kissing before marriage is considered by most Islamic jurists as not acceptable. Even a peck on the cheek would be considered inappropriate. The idea is to not allow things to get out of hand with one thing leading to another.
Kissing During Engagement
Kissing a partner, say, fiancé, during the engagement period–since it is the time before the marriage contract, then it is considered haram or unacceptable. The same thing applies to be thrilled manually by fiancé. But if it happens after the marriage contract, then there is nothing wrong with it. You may also read Converting to Islam for Marriage, What to Expect?
There is a hadith about a man kissing a non-mahram woman.
Ibn Mas'ud (May Allah be pleased with him) reported: A man kissed a woman. So, he came to the Messenger of Allah (ﷺ) and informed him about it. Then Allah revealed this verse: "And perform the prayer, between the two ends of the day and in some hours of the night. Verily, the good deeds efface the evil deeds (i.e., minor sins)." (11:114) The man asked the Messenger of Allah (ﷺ) whether this applies to him only. The Messenger of Allah (ﷺ) said, "It applies to all of Muslims." (Sahih Al-Bukhari and Muslim)
Allah says: “Women impure are for men impure… and women of purity are for men of purity…” (Al-Noor 24:26 – Yoosuf Ali translation of the meaning). If a Muslim already committed such an act, then repentance is important on the part of both parties, but it is not acceptable to stack up to the marriage contract until after the waiting period. You may also read Basic Things to Know Before Marrying a Muslim.
Also, there is a fatwa in Arabic saying, “Do not forget sincere repentance and expiation with real regretting and turn the sins into good deeds like praying, fasting, and doing good things. Being a good Muslim and not redoing those sins is what it takes to be forgiven.”