At first Sally’s disappointed that she didn’t get to see Mark and Tristram sexily joust over her, but Tristram took a spear-wound for her, which is very nearly as sexy by Sally’s standards.  Sally is so into Tristram’s wounded status that what with one thing and another they never get around to binding his wound, and pretty soon there’s blood and such all over Sally’s bedsheets.

Which would be fine, except that a chambermaid bursts in and warns Sally that her husband, Earl Segwarides, is on his way!  So Sally hustles Tristram out of here and he rides off, still bleeding.

In comes Segwarides, not five minutes later.  He sees Sally’s bed all rumpled, as though she’d been rolling around in it with a man who was bleeding from an open spear wound.

“Hi honey,” she says.  “I can totally explain!”

“False traitress!” thunders Segwarides.  Out comes his sword!  “Tell me who was here!  And then I’ll kill you!”  Not the most compelling bargain, dude.

“Okay, so, let’s put the sword down and have a nice civilized chat where I don’t get my head cut off at the end of it, all right?”

“Tell anon to me all the truth!”

“Okay.  Okay, you win.  You’re the big mister swordy man.  It was Sir Tristram — he burst in here, all sweaty and bloody and hot, and we ruined that bed.”

Segwarides howls, and demands to know where Tristram went.

“He rode off just a few minutes ago.  You could probably catch him — if you really want to.  He’s a fine, well-formed knight with a fully-functional sword of his own, you know.  More of a knight than you shall ever be!”

Segwarides pulls on some of his armor — not all of it, he’s in a hurry — and catches up to Tristram on the road back to Tintagil.

“Turn, false traitor knight!” shouts Segwarides, as he closes on Tristram.

Tristram turns, and Segwarides knocks at Tristram with his spear, breaking it.  Then Segwarides pulls out his sword, and stabs at Tristram.

“Hey, now, I’m starting to get annoyed,” says Tristram.  “Knock it off, buddy.  I don’t know what you think I’ve done, but I don’t know you from Adam…”

“Die die die!” screams Segwarides, foaming at the metaphorical mouth.

So Tristram draws his sword and cuts Segwarides.  He also cuts Segwarides’s horse.  In half.  Segwarides goes down, in the wreckage of his horse! Tristram leaves him there and high-tails it back to Tintagil, where he climbs into his bedchamber and roughs it up a bit.  Tristram makes it look like he was roused in the night, and walked into a rake he’d carelessly left by his bed, and that’s why he’s wounded.  No reason to think he was fighting anyone, no sir.  Plausible deniability, that’s what Tristram’s after.

Meanwhile Segwarides’s men find him lying there on the road to Tintagil, the ruins of his horse flaming all around him, and they drag him away before the fire reaches the horse’s gas tank, and they get him home and he slowly convalesces.  Segwarides wants nothing to do with Tristram afterwards, what with the affair and all.  He doesn’t pursue his vengeance further, after he’s calmed down, because Tristram is a deadly foe and the king’s nephew and so on.  Tristram never hears about this because he doesn’t know Segwarides at all.  He knows, vaguely, that Sally has a husband, but that’s it.

And as for Mark, well, Mark knows that Segwarides has reason to hate Tristram, and also reason to hate Mark, inasmuch as Mark was also sleeping with Sally.  When Tristram calls in sick to court and explains that it was the darnedest thing, he woke up in the middle of the night and accidentally impaled himself, that’s why he’s wounded… Mark knows it’s not true, because Mark knows he stabbed Tristram with a spear.  From that day on, Mark secretly resents Tristram, and doesn’t love him any more.  He’s all, oh, Tristram, my beloved nephew but on the inside, he’s thinking I wish adders would eat your face.