Aaron felt Eliot slowly harden under his touches; his licks, his soft squeezes, his lips. He took a moment of attention to his balls, sucked them each, softly, then harder.
Other options:
no subject
Aaron felt Eliot slowly harden under his touches; his licks, his soft squeezes, his lips. He took a moment of attention to his balls, sucked them each, softly, then harder.