does sexual intimacy affect a relationship positvley ?

It depends. If your relationship is based of of sex 10/10 it won't last.

My dad always told me sex will make or break a relationship. I would learn if a guy loved me or was using me or would break my heart. He said make sure it was the right time make him wait!!!

Great advice!!

Yes of course. There is no more intimate act.

Considering that during sex, two bodies become one flesh - that is certainly a profound effect.

But it depends upon the circumstances. Scripture teaches that if a man has sex with a prostitute then he becomes one with her. Thats not good.

But in a godly marriage, sexual intimacy actually strengthens the marriage.

1Co 6:15 Don't you realize that your bodies are actually parts of Christ? Should a man take his body, which is part of Christ, and join it to a prostitute? Never!

1Co 6:16 And don't you realize that if a man joins himself to a prostitute, he becomes one body with her? For the Scriptures say, "The two are united into one." [fn]

1Co 6:17 But the person who is joined to the Lord is one spirit with him.

1Co 6:18 Run from sexual sin! No other sin so clearly affects the body as this one does. For sexual immorality is a sin against your own body.

1Co 6:19 Don't you realize that your body is the temple of the Holy Spirit, who lives in you and was given to you by God? You do not belong to yourself,

1Co 6:20 for God bought you with a high price. So you must honor God with your body.