Many people writing about David & Jonathan obsess over whether or not the relationship between the pair contained romantic or sexual elements, or whether it fits modern conceptions of gayness. Did Jonathan's removal of his robe imply sexual activity? Probably not in that specific instance, and there is no direct evidence of a romantic or sexual relationship between the pair. Even the slightest whiff of an implication of homosexuality has, historically, been enough for modern conservative commenters to clutch their fragile definitions of Straight Masculinity like a scandalized old lady protecting her pearls.Queer-positive theologians argue that the perfect third feminine singular conjugation of "bound" in 1 Samuel 18:1 (above) "details the beginning of an attraction," and places Jonathan in a feminine attitude towards David, one of the limited numbers of ways that the Hebrew language at that time could express a relationship outside of a cishet pairing.
The modern obsession with where the dicks went or didn't go, however, only outlines modern insecurities and obsessions. It not only isn't meaningful, it's the opposite of relevant or helpful when talking about David & Jonathan. So let's start there: where the dicks (and other sometimes-sexy bits) went or didn't go doesn't actually matter.

David (דָּוִד, "beloved one"), son of Jesse, the youngest of eight sons (with at least two sisters) grew up without expectation of much inheritance or much of anything that he didn't work for himself, while Jonathan, the son of a king, grew up expecting to inherit, well, a kingdom. It's important to me personally, as a Jew by Choice, to note David's great-grandmother was Ruth; he descends from her child with Boaz according to the Book of Ruth. As a child, he tended his family's sheep; the prophet Samuel came to anoint him as the third King of Israel after Saul (the present king) angered HaShem by offering an improper sacrifice and defying a direct order to complete destroy the nation of Amalek (עֲמָלֵק) and all of their confiscated property. ("You didn't do a war crime like I told you to so I'm unseating you," not the best look, G-d, but that's another story.)
After G-d sends an evil spirit to torment Saul for -- again -- not doing war crimes on command, David is brought into court to play the lyre and soothe the king. It is in doing so that David is said to have loved Saul very much -- we have no reason from the Tanakh to doubt that David was anything but loyal to his king. "And it would be, that when the spirit of God was upon Saul, that David would take the harp, and would play with his hand, and Saul would be relieved, and it would be good for him, the spirit of evil would depart from him." Leading a country is difficult work at the best of times, and who hasn't had stress or mental illness soothed by good music?
There's a lot to be said about the recounting in Samuel's obsession with the uncircumcised penises of the Philistines and the fact that bounties were collected by foreskins, but pretty much all I'm going to say about it is that David, when referring to Goliath, calls him an "uncircumcised Philistine." What's more interesting to me is that David wasn't part of the army at all -- he wasn't even supposed to be here today -- but had come to bring cheese and bread and corn to his brothers, who were in the army.

It is after the "youth, and ruddy, with an attractive appearance" slew of Goliath with one of the "five smooth pebbles from the brook" which he put into his shepherd's bag that we first have record of David coming into contact with Jonathan, who immediately "loved him as himself." This is the second time that we have record of Saul and David interacting directly, but for Jonathan, it was pretty much love at first sight. This skinny little twink comes up carrying the severed head of a giant, probably covered in blood because hacking off a head with a sword is ugly work, and Samuel tells us repeatedly that David is not comfortable with a sword because he's just a shepherd. He got good with a slingshot by killing bears and lions who came after his family's lambs, after all! Jonathan takes one look at this blood-covered twink in his moment of triumph, and he falls in love.
I mean, fair, right?
Jonathan (יְהוֹנָתָן, Yehonatan, "G-d has gifted,") as the eldest son of the king, expected to inherit the kingdom; David's popularity should have threatened him, because in the time that followed, David became incredibly popular through his military prowess and artistry. When they credited Saul with thousands of Philistine deaths, they credited David with tens of thousands, and Saul became jealous. Jonathan, though, trusted David and loved him -- they "made a covenant" with each other & Jonathan gifted David with his own clothing and possessions: his cloak, his garments, his bow, his sword, "and even to his girdle."
(Much and more has been made of the idea that taking off all of this clothing would have left Jonathan naked, but nudity taboos are much smaller when people live communally, especially between people of the same gender, and honestly -- do we think the son of a king doesn't have more than one thing to wear? This passage talks about Jonathan upgrading the wardrobe of the son of a shepherd, don't get it twisted.)
Saul's jealousy leads him to attempt to kill David by sending him off on a military mission he expects to fail, a tactic that David will himself later use in the sin that loses him G-d's favor, and when that fails, he attempts to assassinate David. However, Michal, Jonathan's sister and David's wife, helps him to escape. David remains an outcast despite a few brief attempts at reconciliation with Saul, to whom he remains a loyal subject despite Saul's jealousy.
David meets with Jonathan only one more time and they renew their covenant, after which Jonathan is killed at Mt. Gilboa along with two of his brothers; his father dies, asking an Amelakite to kill him because "a shudder has seized me," and the Amelakite takes Saul's spear and kills him. The man who killed Saul brings his crown and arm band to David, knowing him as the inheritor of the crown of Israel.
The fact that David receives his crown three days after the death of Jonathan is part of why we depict the crown on David's head -- it shows the tragedy of David's ascent. He could only be crowned properly after the death of the one who he loved as his own soul; he could only gain the kingdom of Israel by losing the love of his life.
"I am distressed for you, my brother Jonathan, you were very pleasant to me. Your love was more wonderful to me than the love of women!" David cries, eloquent even in his grief. No one will ever be closer to David, or more loved by him, than Jonathan. In the years to come, he brings Jonathan's disabled son, Mephibosheth (מְפִיבֹשֶׁת) into his household and treats him as one of his own children.
The modern obsession with whether bits went into other bits betrays the depth and breadth of this love, and betrays its queerness. Within our modern community, asexual and aromantic people form lifelong partnerships and covenants with one another which have nothing to do with romantic or sexual love. These are no more or less queer than those partnerships which center on sexuality and romance. It is undoubted that Jonathan and David were the loves of one another's lives. Perhaps their love involved sweaty naked time. Maybe it didn't. Maybe it involved romantic love. Maybe it didn't. Maybe it was a secret third thing, undefined. Certainly they didn't have the same language as we did to talk about it, in the very least because I'm writing about this in English and not Biblical Hebrew. Every attempt to definitively pin David and Jonathan's love in some way which fits our modern archetypes fails. We not only need not do it, we shouldn't do it. It was what it was, and that is enough. What matters to us as queers today is exactly that, actually: we don't have to define our love for each other in the prescribed fashion to know that it's love, or that it's queer.