Its perfectly fine. Guys have nothing against it. Some even like it. (I tend not be attracted to promiscuous people in general, for instance).
However you should be careful about guys who do not reciprocate the same values as you, but who pretend that they do. Some men know that women from that part of the world tend to be more 'conservative', 'submissive', 'monogamous' or however else people like to describe it, and target those women because they want to exploit those traits of theirs, whilst those men feel entitled to flirt with and hookup with other women.
Equally (though less frequently), there are some women who target men in a similar way. I had a minor row with one of them on this forum few months ago. Some of them have an 'awakening' around their 30s and decide overnight that they want a 'serious partner' despite not demonstrating almost any of the same traits that they expect of the other person. Such a lifestyle change takes time & investment, and is something which these sorts of people rarely have the patience for or commitment to accomplish. Instead they want to 'snap their fingers' at the age of 30 and latch onto another person who has accomplished what they themselves failed to. It is parasitic.
If you are someone who desires a monogamous relationship, you should expect any man whose in a relationship with you to behave the same way. Don't ever compromise or listen to someone's excuses if you end up a relationship with a guy who feels entitled to a monogamous woman, but wants to flirt & hook up with other women. Just leave.
And use your common sense: a person's past choices are reflective of their values, regardless of what some people will tell you. If someone has a track record of partying and hooking up all over the place, it likely says something about them. It is not 'irrelevant' either for men or women. Most of the people I've known who were obviously promiscuous had quite 'flexible' morals, and for instance saw little wrong with bulsh*tting their way into someone's bedroom (usually for men), or bullsh*tting people into buying them a free dinner or free drinks on a night out (usually for women). People can grow out of this mindset and lifestyle, sure, but like I already said it takes time and is not a 'snap of the fingers'. Entering into a serious relationship with someone like this is dangerous: they are not trustworthy. If you lent someone £5 and they didn't return it, would you lend them £500 and trust them to return it? No.
I probably answered more than you asked for. UK 'dating culture' and relationships work very differently to Pakistan. It is a lot more liberal, and its worth being aware of its downsides. The upside is of course, you are usually free to leave abusive / exploitative relationships with people like this, or avoid people like this altogether, unlike in some parts of the world.