The Bible does not forbid close friendships between men and women. As Christians, however, there are some principles that we would be wise to heed. Married people especially need to be wary of friendships with members of the opposite gender because temptations are more likely to arise when there are marital problems. If a man’s best friend is a woman who is not his wife, he is likely to share these problems with her, which can lead to an unhealthy emotional attachment. The same holds true for a woman who has as a best friend a man who is not her husband.

Most married people who have affairs don’t purposely go out to find a romantic interest outside of their marriage. Many people say, “I didn’t mean for it to happen; it just happened.” But these things “just happen” when we “play with fire” and put ourselves in situations that are difficult to control. When we feel a spouse is not attentive to our needs, we can easily feel that we have “fallen in love” with someone else who does give us the attention we crave. When we feel ignored or under-appreciated by a spouse, we should communicate our struggles with the spouse and avoid the danger of seeking comfort elsewhere.

Even a marriage that is built on a foundation of faith in Christ and has relatively few problems is not immune to extra-marital temptations. This is why the Bible does not tell us to stick around and try to fight temptation, but to flee from it like we do from all "youthful lusts" (2 Timothy 2:22). Trying to fight temptation seems to become especially difficult when it comes to matters of the heart or the lusts of the flesh. First Corinthians 6:18 tells us that we need to run away from sexual sin, because it is much easier to run away from temptation than to stay and fight it.
Married men and women should carefully avoid putting themselves in compromising situations when it comes to the......
https://allsinglesandmarried..com/2019/11/is-there-any-reason-why-married-person.html

Maka why

Why should someone who is of the opposite sex be your best friend as a man or woman? That is an error! While no law bars either party from be friends with the opposite sex (cause the person could be your colleague in the office or old school mate or someone down the street etc) however, such friendship must be guarded by some principles. For example each friendship must be strictly defined. Also the Bible says flee from all appearance of evil. That is once the friendship starts turning a direction outside your limits, you back off.

Flee all appearances of evil before your penis will mistakenly fall into her vag, or she will mistakenly trip and fall on his penis.