Sasha doesn't love Kaleva.
That's why he ran away when Kaleva said he loved him. That's why he had sex with someone else. That's why he asked Harry for whatever-it-was rather than Kaleva, even though Kaleva would give him whatever he wanted and not ask for anything in return and certainly not make him limp-- because it's easier to do a single close-ended trade with a known cost you can pay than to take a gift from someone who only wants you to love them back.
It makes sense that Sasha wouldn't love him. Sasha is very attractive and has been with lots of other people. Kaleva is kind of ugly and can count the number of people who have given him positive attention without being paid for it on one hand with fingers left over. Kaleva is from Auradon, where people get married four days after meeting each other. Sasha is from the Isle, where love is a weakness that gets you killed.
He sits six inches away from Sasha. He doesn't touch him. He jerks away when Sasha tries to kiss him. He does the tutoring, because he promised and Sasha needs him, but if Sasha tries to bring up a different topic he goes back to talking about homework. He moves to a different table when Sasha tries to sit with him. He stares open-mouthed at Chen when Chen strips off his jersey; he doesn't feel guilty. He keeps an eye out for other guys he's attracted to, makes a list. King Ben, Prince Asher, Mordred. No one who is likely to be gay or is remotely attainable even if they were.
It occurs to him that if things had worked out differently he'd be having a crisis about whether he was really gay or whether gay people were capable of love or whether gay sex was wrong. But his feelings about Sasha are so obvious they've crowded out the other worries. Obviously, he's gay; he's never felt like this about a woman. Obviously, he is in love. And if gay sex is evil he cannot possibly bring himself to care.
He doesn't cry.
He doesn't feel much of anything at all.