David and Jonathan's first meeting is intense:

Now when he had finished speaking to Saul, the soul of Jonathan was knit to the soul of David, and Jonathan loved him as his own soul. Saul took him that day, and would not let him go home to his father’s house anymore. Then Jonathan and David made a covenant, because he loved him as his own soul. And Jonathan took off the robe that was on him and gave it to David, with his armor, even to his sword and his bow and his belt. 1 Samuel 18:1-4

From that moment on, they were very close, putting the other before anyone else.

This blogger digs deep into the queer subtext:

https://blog.smu.edu/ot8317/2016/05/09/1-samuel-18-23-the-queerness-of-david-and-jonathan/